Unfortunately, there is an age old reason why games are often buggy on release, and it often goes like this:
- Developer gives publisher a timetable, which may slip early on, but publisher monitors progress and often requires proof of progress updates.
- at least 6 months before expected release (if not more), publisher sends out notification so stores can order copies (which gives publisher an idea of how many copies to print) - this is almost always contrived to be 3-4 months before Christmas, no matter where team progress is.
- Developer realizes they can't meet the date with the number of bugs and asks for an extension, which publisher refuses or in some cases, the publisher gives the title to another dev team to polish and fires the existing development team (which is my experience, thank you EA).
- Developer squashes as many critical bugs as possible, but the game still ships on the date.
- Developer scrambles to put together a zero day patch, or at least one soon after release (there is generally about a month between when the developer hands it off and the publisher publishes it), because they care about customer experience and publisher only cares about their investors.
I'm guessing developers like Blizzard and Arena Net are usually in late beta when they send their notice to stores and spends the last few months doing nothing but polishing, but I do know those two will refuse to publish if the game isn't done. The team I was contracting for was in mid-alpha when ship was set and late beta when we were fired (a month before it was due in publisher's hands).
It isn't much different in the corporate world, but instead of a publisher forcing the date, huge customers do. I've worked in both worlds.