Without getting into your overall premise, Peter Thiel is gay.
So, I'd respond to what you seem to be implying by pointing out that Sheriff David Clarke also exists. So do anti-immigration immigrants. There's also a phenomenon called Stockholm Syndrome.
Doesn't really prove anything except that counterintuitive ironies exist and that people don't always act in their own best interest and/or they make tradeoffs. It's actually rational to not be a one-issue voter, especially in a two-party system.
In short, a gay person being a member of a party doesn't make that party pro-gay rights.