It strikes me as a little odd that an empire's entire citizenship is always the same race.  If I'm a Camaar and I overtake a planet from a Quantam, all of that planet's population is now a different race?

That doesn't make any sense.

I'm not ripping races out of the game, but what are your guys' thoughts on this as a narrative construct?  Is it the result of genetic engineering?  Is the populace executed and replaced upon every planet capture?  Should we be calling "Race" something else entirely?

This is obviously a minor detail, and doesn't have an effect on game play.  Still, little thematic things like this color the feel of the game, so they're worth examining.