We should all date who we are attracted to, Simple

Human sexuality is fragile. Straights (and quite surprisingly gays) are reluctant to do anything that might bring their heterosexuality (or homosexuality) into question, either in their minds, or those of other people. I've actually had more outright hostility from drunken homosexuals who fancied me but felt they shouldn't, than from drunken heterosexuals who felt the same.

So yes, trans people tend to find romance either with other trans people or with bi/pansexuals. Things are improving with respect to trans people being treated as their identified gender, socially. But we're a long way off them being treated as their identified gender, sexually. Besides, for those not going down the surgical route, I don't believe it's reasonable to expect (for example) a heterosexual male to be interested in having sex with someone who has a penis. There's absolutely nothing wrong with having a strong (even exclusive) genital preference. Even post-op, there's the fact that a lot of partners expect to start a family, and that's no longer an option.

There are an alarming amount of transphobic people in the LGBT community. I’ve met more than a few TERFs at LGBT events.

I can’t really see this as an issue. People have preferences. Nothing wrong with that. The percentage may go up in time, but it will always be a minority of people who will be willing to date transsexuals. It sucks, but it is what it is.