Thing is, how many people do really make their sex life a dominant part of their personality? If you think about it, do heterosexual people make their sex life the dominant part of their personality?
There are, absolutely, some people who are sexual predators and that does define them, but that is not an exclusive preserve of non-heterosexuals, quite the reverse, even if just by sheer numbers.
For most people, their sexuality is just a small element of their make up. It is more an issue of perception of someone who is not the same as you. Very simply, years ago anyone who was gay would be given a wide berth by members of the same sex, because they may be 'fancied' by them. Truth is they would probably not be attractive to that gay person who would more likely prefer to make a play for someone who may be on their wavelength, not just because they are the same sex.