SEGA published the game, the Creative Assembly made the game (although now owned by SEGA). Badly. I really wish I could roll back to 1.2 when my game had working sound.
CA need to update their game: it's broken for many, many people. The support forums have many people with game-breaking bugs right now. CH are doing an excellent job at keeping up to speed with CA's incompetence, in my opinion.
I don't think anyone is complaining about CH.
CA on the other hand have been utterly naff. Asyncronous sound (introduced in 1.3) ruined the only part of the game which was working fine for me.
The game simply wasn't tested properly. Too many CTDs and whatnots. And judging by the fact 1.3 broke more than it fixed, I'm guessing their patches arn't tested well either.