The more-or-less accepted theory is that, due to the over-reliance on romance and sex, they didn't want to deal with having a dateable short-race character, so Helia got benched in favour of Halsin.
Bears are fine, though, is what one's getting from this.
Regardless, having a, say, Korgan- or Khelgar-like dwarven fighter would make them stick out like a sore thumb with all the oh-so-special companions that is everyone else on the crew. Too "generic", too "dull". Not layable enough or something.
