Civ 5 alone would not have made me post this. It only contributed. I feel like the majority of games the come out for pc are incomplete. My examples are Settlers 7 and Hearts of Iron 3. Why do we not see this with console games?
I take your point, and I think I overreacted a little with my initial take on the poll. I think there are a few reasons why it's more of a problem for PC's.
Hardware configurations are so much more varied for PC's compared to consoles, and they only get more varied with time. New drivers and hardware flood onto the market constantly, that coupled with the fact that lots of people still use older generation equipment means the different PC variations are massive, and constantly expanding.
Add on to that the various levels of abstraction like OS's, localisations thereof, hardware drivers, and everything else and it's a huge list. This alone makes QA a hugely different task.
It's just a far different beast than developing for consoles, and it means there is less time to devote to play testing, balance and every other facet of a game - at least I believe so. The potential earnings for games now are massive, but so are the costs. I picture QA and testing being the only part of development which doesn't scale in the same way.
Some companies do still manage to consistently release very polished games (only Valve and Blizzard immediately spring to mind), but they tend to be special cases with the ability to release and develop without being as constrained by budget
Lastly I think the economy is playing a part. Most businesses are under extra economic pressure which does factor into rushed releases.
The internet also makes releasing something in need of some love that much easier, which is a double edged sword. Even console games receive patches now. The landscape for what is reasonable to patch and add on after release has changed as a result, and those additions and game-play patches are now becoming a part of the accepted norm.
