This is a valid question, which could also be asked of Alien. It’s as simple as some people like to be scared, whether to explore personal feelings on a specific type of fear or purely to be scared. For some players, that a game addresses a fear they rarely explore is an enormous bonus.

Your confusion is understandable. Games that directly address the same themes of sexual violence as Alien are a minuscule niche inside an already small niche. But I can tell you as a horror GM that even a whiff of an exotic, earnestly held fear, as long as the player is willing to engage, cuts deeper than hours of classic slasher horror. It doesn’t have to go as far as even Alien, just a little taboo horror as seasoning, but even that needs consent.