No, players are not the one being discriminated against. Just that it would make it basically impossible for a dragon to find smaller dragons, or for someone to find particularly large amazonian characters. What if one of the defining descriptions of your character is that they are an otherwise small species that is quite large? Maybe a human-sized goblin? A dragon-sized fish? Too bad, you're screwed out of any way to list that and for anyone to find you by that.
For finding a large Amazonian I would use human and tall. For a human sized goblin, goblinoid and average. For a dragon-sized fish, fish and macro. On the other hand, how it is now, one cannot find large amazonian chars or human-sized goblins and dragon-sized fishes. Since human+large and fish+macro and goblin+macro don't give information about the actual size of the human, the goblin and the fish.
What's big for a human? 6'? 5'? 7'? Depends on your gender and where you live. This suggestion would flatten all human variance based on the lens of what is average for a western male of about moderate age. That's not exactly representative of all humans everywhere.
Does that mean, age and race and country are to take into account if I set the body height? A 5 years old which is three feet tall is "tall"? A Masai who is 7 feet tall is "average" but if he lives in the US he is "tall"?
Someone looking for giant characters would need to search for giant species as well as Body Height. Dragons, titans, amazons, and the like. Someone looking for smaller characters would need to search for pixies and the like. And when they search for both of those things at the same time, there's going to be a lot of missed calls. Worst of all, it's confusing and complicated.
What I meant was, if someone is looking for characters that are really big, they would need to search for the macro trait, and then run a separate search for big species. The first search would turn up human-sized cats, dogs, squirrels, and the like. The second search would turn up human sized dragons and the like.
I think the profile framework is more than flexible to handle these things, so the focus should be on making it easy for users searching.
You cannot search for pixies since there is no such species. It's vice versa, to find a pixie you need body height, since a pixie is demihuman just like a titan. There is no "dragons and the like". Dragon is the only large species we have. So to search for large species you need "macro".