Por que a tripulação do Nostromo destruiu o navio?

A tripulação do Nostromo foi guiada pelo medo de que se simplesmente abandonassem o navio que o Xenomorfo infectaria com sucesso qualquer tripulação que viesse salvar o Nostromo e que Weyland-Yutani continuaria com seu plano levá-lo para a Terra, onde poderia causar um surto.

Ash (na novela ) fala muito bem;

'I cannot say. There is a distinct possibility the alien will successfully infect the boarding party and any others it comes in contact with before they realize the magnitude of the danger it presents and can take steps to combat it. By then it may be too late.

'Thousands of years of effort have not enabled man to eradicate other parasites. He has never before encountered one this advanced. Try to imagine several billion mosquitoes functioning in intelligent consort with one another. Would mankind have a chance?

'Of course, if I am present and functional when the Nostromo arrives, I can inform the boarding party of what they may expect and how to proceed safely against it. By destroying me, you risk loosing a terrible plague on mankind.'

_{^{Alien: Official Novelisation}}

HUNTER: Blow the ship up?

ROBY: And the creature with it. We can make it back to Earth in the lifeboat.

Ok, então depois de ler o script eu encontrei aqui , em um ponto que um plano de simplesmente abandonar o navio foi sugerido e prontamente descartado.

Ripley: Unless someone's got a better idea about dealing with the Alien, we'll proceed with Dallas' plan.

Lambert: And wind up the same way. No thanks.

Parker: You've got a better idea.

Lambert: Yes. Abandon ship. Take the shuttle craft and get the hell out of here. Take our chances on getting picked up later.

Ash: You are forgetting something. Dallas and Brett may not be dead. It's a ghastly probability perhaps, but not a certainty.

Ripley: Ash is right. We've got to give it another try. We know it's using the air shafts. Let's take it level by level. This time we'll laser seal every bulkhead and vent behind us until we corner it.