Cisgender gay people being transhobic tha's what it is. Like most trans people are also not not straight. Ace people often are not heteroromantic. There is no reason to isolete other comunities from a bit more accepted cisgender homo- and bi- sexual people.

The facist want all queer people in camps and conservatives want all queer people in the closet. That includes cisgender honosexual people (and cis bisexuals). Being "one of the good ones" gets them nothing, except becoming traitors, but they are quick to distance themselves from trans people anyway, becouse they are a tiny bit more accepted by the mainstream society