Well, let me see what I can do about that:

Most of the time, I don't like it. I almost always get hit on by the wrong sex, and I'm not very "why not" about it because I am not looking for friends, really, or awkwardness down the line when they try to take it to another level.

Even if it were the right sex, I don't like having to reject people and never know how they're going to react to it. At least half of the time, they don't just take no for an answer, especially if you're trying to be nice about it. And most guys have no idea how to hit on women properly, so the way they approach is not really flattering, to me, with maybe 2 or 3 exceptions I can think of ever and I'm mid-30s. There are also some cultural differences in how men approach women, and my specific culture is probably one of the worst in terms of all these things, i.e. the way men approach and not being able to take no gracefully or at all.