FFXIII and Versus-XIII (which most people are looking forward to) kind of proves the engine isn't crap. XIV's optimization is very very poorly done. There's a lot of games out there that are horrible built on the havoc, CyT and Unreal but you wouldn't call the engines crap.
But he would just make a better RPG, which people say are bad for MMORPGs. They have to be action based platformers based on current standards as people say. So partnering with them would actually hurt the game more based on current MMORPG gamers.