Game “X” didn't sell poorly because it sucked. In fact, it probably sold well. The problem arises when so much capital is required to develop and publish a game, forcing companies to move obscene numbers just to turn a profit. That's the reality of modern top-tier games. Creating assets that utilize hardware potential or at least rival what other companies output, corners developers to create AAA games, from day one. That’s just not practical. Call of Duty may sell 20 million units, but it's a rare phenomena. There's simply not enough gamers out there, with enough cash to buy every decently crafted, AAA game.