Fighting generalizations with more generalizations is meaningless. Sorry, but you're doing the same thing they are. I mean, most western games are 8 hours? I've put tons of hours into Fallout New Vegas, Torchlight 2, AudioSurf, and Borderlands 2 over the last six months. What about Elder Scrolls, Mass Effect, and Dragon Age?
These generalizations accomplish nothing. If you want to defend Japanese games, fine, but trying to do that by lumping all western games together serves no real purpose.