Well, for me, we have two female companions currently. Lae'zel is ugly and angry all the time and is simply a fighter. SH has been softened up personality-wise and she's attractive, and she heals and can be the group rogue.
I have no opinion on the other female companions because we don't know for sure yet what they'll be like, although I have my suspicions sarcastic and blunt will be defining personality traits, which will turn me off. Honestly, the only reason I can stand SH now is that her edginess was toned down a lot.
Haha yes, your first paragraph was what I meant by "...other reasons." xD