Avistew wrote:but to be honest I've always wondered what gay men and women had in common (they're different genders who like different genders. Not much overlap here) or what either had in common with a straight trans person.
The focus is, I think, on shared experience: shared experience of not seeing yourself represented in media; in what are often troubled coming out processes; of being discriminated against legally and socially; of struggling to figure out how to have a relationship when you're not raised to know what one is supposed to look like; of figuring out who you are and what you like when your assigned gender doesn't quite fit, at least not out of the box. A lot of LGBT groups are about activism and fighting for visibility, representation, and legal protection, which is where LGBT people are all on common ground.
And, none of these things are directly related to the sex you have or don't have.