There is no LGBT community

[Genersis]

You are right, in that there isn't a single unified LGBT community.

Though people with commonalities often form communities.
Sexual and gender minorities often operate together politically due to the similarity of the struggles they face, this often leads to communities of these minorities forming.
It's not exactly rocket science.

By no means must you participate in a community.
Though you may be able to find a strictly gay men community that have the same problems with the other minorities as you; but I think that could be quite difficult.

Regardless, if I were you, I wouldn't waste time and energy getting annoyed over something you have no control over.
Others aren't going to change just because you don't like lesbians.