I get the impression that many people see others as potential sexual material.
I've noticed, when I'm with men at work, the talk is often about any women they see and if they would 'do her'.
The reality is, of course, that few if any of these men would get a look in from most of the women they oogle, but for them, it's an affirmation of their status within the pack.
Women also seem to do this, but more often, they tend to see other women in term of the competition they might present in attracting some specific guy.
So, for both men and women, homosexuals and transsexuals present additional possibilities.
Men, certainly to other men, seek to affirm their own manliness, by rejecting homosexuals and transexuals. I suspect they are more concerned with the show than their own feelings.
Women, on the other hand, seem to consider homosexuals and transexuals in terms of the potential competition they might present.
Personally, I usually, but not always successfully, avoid problems by making it clear that I'm not intersted in any relationships with anyone.
This is made easier by the simple reality that I'm really not.