First, allow me to clarify that I'm not sold on any of the discourse about "basilisks." Yet since that word is so popular on LW, I decided to use to it to characterize an idea that has the capacity to destroy the quality of life of some people.

Your paraphrase of the idea ("people don't always have the same romantic ideas") makes it sound harmless. Here's how I put it originally:

Reflecting on the massive diversity of female preferences and assertiveness about their boundaries can be frightening to many men.

If the variance of female boundary-assertiveness (people-pleasing, etc...) is large enough, then X% of women may be vulnerable to complying with male advances that they do not want. This principle could be true of any advance that a man could make.

Even if X% is low, this notion is still highly disconcerting to some men, and can motivate some of them (e.g. my past self) to refrain from making any advances. For men who aren't significantly above-average in attractiveness, this usually means being alone. This outcome is severe enough that it overlaps with what some people on LW call basilisks.

Of course, my reference of that meme doesn't mean that I endorse it, nor do I want to shutdown discussions of these possibilities. Instead, I want us to examine these possibilities and articulate sexual ethics that make sense.