Vagabund on 20 October 2009
I would say it's mainly the decrease in popularity... which didn't start with ToD, every game so far sold less than the one before. There was probably just too little innovation to let the series grow, so even though ToD is a great game, it's not that different from previous iterations. The smaller install base is probably another reason, since it's a game that also many "casual" gamers enjoy - a userbase that the PS3 is still lacking compared to the PS2.
