Once again guessing, I'd say that "queer" and "bent" were both at a time abandoned by the gay community (even though "bent' is of course the actual counterpart of "straight") because of the negative connotations of weirdness in the former case, and something that's not in its proper shape in the latter. "Gay" persisted because it was the first name whose alternate connotations were positive (being merry/carefree).

I don't know why "queer" became acceptable to be reclaimed again, but I'm wondering whether it's because "weird" is not really seen as a bad thing anymore -- "geek" has also become a badge of honor after all, though it once used to be an insulting word.