Totally random thought

So what if, instead of categorizing ourselves by whether we're attracted to same-sex or opposite-sex people, we split off into tops and bottoms? Or attracted to men/attracted to women? Or butch/femme? Or casual/serious?

All of these things are just as important, in terms of how we relate to other people on sexual and friendship levels as whether we're attracted to people who have the same genitals we do or different ones. So why don't we think of them that way? Why don't we arrange ourselves in groups according to those commonalities?