It's easy for someone who is not the CEO of a company like Activision to say "just drop them" when that CEO stands to leave 10's of millions of dollars on the table by "just dropping them." If the financial potential is there, and it is, you would be an idiot to leave that much money behind. There can very viably be 2 versions of the game, 1 for old gen & 1 for new gen. NBA2K, Black Ops 3, and Diablo 3 are all currently doing it, just to name a few.