Seems to me when it's observable that the vast majority of people, including "homosexuals," seek out relationships that approximate---sometimes to the nth degree---male-female relationships, that it has to mean something. It's not nothing.
So when homosexuals constantly organize themselves (and their communities) into male and female dynamics, that has to mean *something.*
One possibility is that heterosexuality is indeed normative and the vast majority of people who participate in sexual/intimate (emotionally and otherwise) relationships do so in a heterosexual way---regardless that they consider themselves "homosexual".
The two sexes in the relationship/dynamic may be an actual male and an actual female, or they may be an actual male and an approximated female (a feminized man) or an actual female and an approximated man (a butch woman). In all cases, the result is still a relationship that has a male-female dynamic.
What does that say about the concept of homosexuality?