There are a lot of people that enjoy Apple product and would rather pay a few dollars for a game that will last them a day rather than buying a full game that will last for months. Apple has a competitive edge in some ways, their games are cheap and there are millions of them. Also more that people have Apple products than people who have video game consoles. If Apple wanted they could enter the console market, but I don't think they will destroy it, but that's not to say that they won't hurt the video game market, they have already done that.