Not many of them, but they exist. WoW holds a record, I believe.
Still, you see, that's the problem. Imagine it's a ship. Modern warships are the most complex technological systems on the Earth. Would people who order and bought new ships comply with explanation "well, you see, it's hard system so it's obvious that your communication system isn't working, and promised marching speed is half of the promised, when it's not breaking at half when it goes around"?
Saying "we screwed up because we have just eight years of developing this particular game, not to mention other games on this engine, not to mention other games" is child excuse. "Sorry, did you expect us to be competent in our job?!"