Por que todo mundo não está pasmo com o "presente" de Bran?

Who in Winterfell at this point would be flabbergasted by Bran's gifts?

Many things have happened in the world of GOT in the last 7 years (in GOT universe time).

Most people in Winterfell have either seen white walkers or believe they exist because so many others have seen them.

The free men from beyond the wall are all familiar with magic, such as some people having gifts to allow them to take control of animals.

Anyone who rode with Stannis saw the powers of the Red Witch.

Varys lost his genitals to a magic user, who used the flesh to summon something in a fire.

Daenerys is all to familiar with magic users, and you know, did the whole dragon thing.

There is also plenty of evidence that some people of Westeros are believers anyways. Even Cersei visited the blood witch Maggi and was haunted by her prophecies.

And Northmen by way of their religion are even more likely to be believers in magic and particularly greenseers. Just look at Jojen Reed.

Add to this that Bran Stark is a Lord of Winterfell and therefore more likely to be believed than a commoner, and I think it would be more strange for people not to believe him at this point.

And if anyone did want to challenge that he knew these things, they would not only be challenging a Lord of Winterfell, but all those who did believe him, including (but not limited to) Jon Snow, Daenerys, Arya and Sansa.

On the show, Bran's powers are more about conhecimento things than fazer things (the books deal much more with his warg nature than does the show, though so far to relatively little ultimate effect), while dragons are pretty much the opposite.

Bran's powers are difficult to casually observe (he said he'd seen Littlefinger do various things, for example, which Littlefinger would certainly know was accurate, but who else would?). Even those who know what he can do might not quite grasp the scope of it-- he can observe events in the past, which is easy to appreciate, but he sort of knows everything that's ever happened in Westeros (possibly subject to some unknown limitations). That's a lot harder to wrap your head around, especially in a setting where knowledge of history is limited to what someone may have written down in a book that happened to survive and which you happen to have had the time to read.

It seems like a fair bet that there are a lot of actual opinions about Bran's abilities. Many probably doubt that he can actually do any of the things he claims he can, and doubt magic more broadly. Others may be more willing to believe that his claims are at least possível. But the main characters of the show have nearly all encountered legitimate magical powers, many of them a lot more unnerving than knowledge of history and current events.

Seeing Arya drink lethal poison and survive, or mystically change faces, or watching a priest raise someone from the dead over a dozen times, or experiencing the mysteries of the House of the Undying, or a woman walk into a bonfire and then rise from the ashes, or seeing a dragon roast most of an army, or watching a field of corpses rise and attack-- these are all pretty dramatic and maneira outside of the norm of what people believed was at all possible. Bran's powers seem a bit more "ordinary", sort of like having extra-fast ravens or having spent a lot of time studying.

Finally, whatever it is that people believe Bran can do, he seems to be very much on his observers' side. At a minimum, he doesn't seem to be a threat to them (compare with a few dragons, which are inherently dangerous even if they estão on your side).

So, in summary, Bran's powers are less dramatic, harder to truly understand, difficult to observe, and less threatening than essentially all other magic seen in the show.

Never forget that for every Bran, there are probably thousands of actual raving lunatics.

While the show doesn't particularly draw attention to it, they still hold notions that to us (the modern viewer) sound archaic. One example is the "only men can be knights" scene from the last episode. There are other cases where it's subtly visibly how only a handful of characters (e.g. Tyrion) used "modern" morality that the viewer identifies with, whereas other (even characters we like) still use (to us) outdated ideals.

So look at it with their prejudiced eyes: Bran used to be a healthy boy. Then he became a cripple. Then he seems to have become mentally challenged. He just stares at you with blank eyes, and then sometimes says something that seems to be a non-sequitur.

Tyrion is a longstanding example of how the disabled are treated. The general populace treats them as inferior or avoid them. In Tyrion's case, he has a sharp mind, and more intellectual characters recoginize that Tyrion is not in any way handicapped in conversation (if anything, he outclasses them).

But Bran does not show the same conversational competence that Tyrion does. He speaks weirdly. We, the viewer, know that he's an omniscient entity and therefore know that his utterances are wisdoms. But to someone who doesn't know Bran's backstory, it just sounds like the ramblings of a decaying mind.

In the last episode, he quoted "the things I do for love" to Jaime. To Jaime (and the viewer), that makes a lot of sense. To everyone else, who wasn't there when Jaime said it, it's off-topic and unrelated to what other people are talking about.
This repeatedly happens. Bran references something that makes a lot of sense to someone, but many others who lack context do not understand him and thus assume he is rambling.

Tyrion was the first to recognize Bran's value and that's he's not just rambling, because Tyrion (of all people) knows what it's like to be dismissed as the inferior and broken human. Additionally, Tyrion loves learning, and Bran is effectively an infinite one-man-library.

Bran claims in front of a large audience including Daenerys that the night king has breached the wall and has one of her dragons.

Who knows whether Bran is correct, if Bran is the only one who knows it? Trust is one thing, but confirmation is another. Before it is confirmed, some people may trust Bran, but the vast majority will not believe him yet. By the time it is confirmed, there will already be an air of "Bran says silly things" which is a reputation that's hard to remove.

Not everyone who speaks wisdom (at a time where it is not yet understood to be wisdom) will later be vindicated when it is revealed to be correct.

Similarly, think back to Bran and Littlefinger's conversation, where Bran quotes "chaos is a ladder" to Littlefinger. Since Littlefinger said that to Varys in King's Landing, LF should therefore realize that Bran is omniscient, and must run for the hills because his secrets are known! Except that he doesn't. LF doesn't understand how Bran knows the quote, but there is a much more sensical assumption: Varys talked about it and Bran found out through some channel. Even if it wasn't Varys, Littlefinger seems likely to assume that someone must have overheard him. There's no reason for him to assume it must be a supernatural phenomenon.

He later speaks in front of the war council in Episode 2, during which many people are present, some who barely know Bran. He speaks of the night king and being the three-eyed raven and the end of the world etc., and no one seems especially concerned.

When someone says something you don't understand, the most common human reaction is to assume that this person is mistaken, rather than thinking you are mistaken.

Because how can you know that Bran isn't just living a childlike daydream in his head? For all they know, Bran is a mentally challenged boy who makes up stories about the things he hears around him.
Never forget that for every Bran, there are probably thousands of actual raving lunatics who are saying nonsensical things.

Think of it this way: your assumption that everyone should listen to Bran because he just might be right; suggests that you think we should listen to cada conspiracy theorist because they just might be right.
This is the same mindset that leads people to e.g. retroactively attribute the gift of foresight to Nostradamus, but only after the allegedely foretold thing has happened; which just doesn't make sense.

I would say that almost everyone in Winterfell at the moment is there because they believe in the White Walkers/Army of the Dead and are there to fight for the living. Jaime Lannister rode up to fight, Theon Greyjoy has come to fight, even the Hound is there to fight. So, the conclusion that Bran Stark is aware of where the White Walkers are and is aware of what they are doing seems less strange because that is the ONLY reason everyone is there.

Daenerys is there to fight the White Walkers ahead of fighting for the Iron Throne, so everyone there is self-selected as someone believing in the supernatural enough to go North in the beginning of a vicious winter to fight them. She is risking everything to fight a magical army, so other related magic must seem only more unusual, not unbelievable in itself.

Also, Bran is very sparing in dispensing wisdom. He will make a claim to knowledge, but only very little about the past. He is not using the power to claim, money, lands, title, or anything like the usual reasons for lying. For example, when others ask if dragon fire can kill The Night King, he says, he does not know because no one has ever tried it before. Most liars will never reveal an end to their knowledge or a limit to their powers. This answer gets Bran nothing personally, and so it is also less suspect.