Bem, em parte, porque como bleh diz em sua resposta , Hermione e a professora Trelawney deram errado pé em vez disso. Logo no início da aula, antes do incidente na questão, Hermione ficou ofendida quando o professor Trelawney declarou que 'Os livros podem levá-lo apenas até agora neste campo'. Isso vai muito contra os métodos e inclinações de Hermione.
'Nobody in my family's magic at all, it was ever such a surprise when I got my letter, but I was ever so pleased, of course, I mean, it's the very best school of witchcraft there is, I've heard - I've learnt all our set books off by heart, of course, I just hope it will be enough - I'm Hermione Granger, by the way, who are you?'
Harry Potter and the Philosopher's Stone - p.79 - Bloomsbury - Chapter 6, The Journey from Platform Nine and Three-Quarters
Também é possível que a professora McGonagall tenha decepcionado Hermione um pouco:
'Anyway, who says the centaurs are right? It sounds like fortune-telling to me, and Professor McGonagall says that's a very imprecise branch of magic.'
Harry Potter and the Philosopher's Stone - p.190 - Bloomsbury - Chapter 15, The Forbidden Forest
Mas principalmente, eu acho que é apenas isso, ao longo da série, Hermione é cética e racionalista.
Por exemplo, você pode lembrar, no Prisioneiro de Azkaban , o coelho de estimação de Lavender é morto por uma raposa. Na primeira aula, a professora Trelawney disse a Lavender que a coisa que ela teme acontecerá no dia 16 de outubro. No dia 16 de outubro, Lavender recebe a notícia e toma como confirmação da previsão de Trelawney. Hermione não está impressionada.
Hermione hesitated; then she said, 'You - you were dreading Binky being killed by a fox?'
'Well, not necessarily by a fox,' said Lavender, looking up at Hermione with streaming eyes, 'but I was obviously dreading him dying, wasn't I?'
'Oh,' said Hermione. She paused again. Then -
'Was Binky an old rabbit?'
'N-no!' sobbed Lavender. 'H-he was only a baby!'
Parvati tightened her arm around Lavender's shoulders.
'But then, why would you dread him dying?' said Hermione.
Parvati glared at her.
'Well, look at it logically,' said Hermione, turning to the rest of the group. 'I mean, Binky didn't even die today, did he, Lavender just got the news today -' Lavender wailed loudly '- and she can't have been dreading it, because it's come as a real shock -'
Harry Potter and the Prisoner of Azkaban - p.112 - Bloomsbury - Chapter 8, Flight of the Fat Lady
Mais uma vez, na conversa com Xenophilius Lovegood sobre as Relíquias.
'But then ... do you mean ...' said Hermione slowly, and Harry could tell that she was trying to keep any trace of scepticism out of her voice, 'that you believe these objects - these Hallows - actually exist?'
Xenophilius raised his eyebrows again.
'Well, of course.'
'But,' said Hermione, and Harry could hear her restraint starting to crack, 'Mr Lovegood, how can you possibly believe -?'
'Luna has told me all about you, young lady,' said Xenophilius, 'you are, I gather, not unintelligent, but painfully limited. Narrow. Close-minded.'
[...]
'All right,' said Hermione, disconcerted. 'Say the Cloak existed ... what about the stone, Mr Lovegood? The thing you call the Resurrection Stone?'
'What of it?'
'Well, how can that be real?'
'Prove that it is not,' said Xenophilius.
Hermione looked outraged.
'But that's - I'm sorry, but that's completely ridiculous! How can I possibly prove it doesn't exist? Do you expect me to get hold of - of all the pebbles in the world, and test them? I mean, you could claim that anything's real if the only basis for believing in it is that nobody's proved it doesn't exist!'
'Yes, you could,' said Xenophilius. 'I am glad to see that you are opening your mind a little.'
Harry Potter and the Deathly Hallows - pp.333-4 - Bloomsbury - Chapter 21, The Tale of the Three Brothers
De fato, é tão característico disso Hermione, que Dumbledore confia nele. É por isso que ele deu Hermione Os contos de Beedle, o bardo.
Eu estou muito com Hermione sobre isso e posso dizer que, se eu estivesse em uma sala de aula com alguém como Trelawney, e eu os ouvisse falando como Trelawney faz na pergunta, eu seria igualmente desdenhoso e desdenhoso. . Outros não e, porque eu gosto de pontos de repetição, eu não vou entrar em tudo isso aqui ...: P Mas certamente não é nada para se surpreender.'I am afraid I counted on Miss Granger to slow you up, Harry.'
Harry Potter and the Deathly Hallows - p.577 - Bloomsbury - Chapter 35, King's Cross