Some Xbox 360 owners are dismayed that their collection of current-generation games won't work on the upcoming Xbox One. But Xbox head Don Mattrick is betting that they're in the vast minority. In an interview with The Wall Street Journal, Mattrick explained the decision not to focus on backwards-compatibility. According to him, only 5 percent of customers actually played older games on a new console, making it a low priority. "If you're backwards compatible, you're really backwards," he said.

On a technical level, the Xbox One can't play 360 games because of its processor. The new x86 CPU can't natively run games made for the 360's Xenon processor, which used PowerPC architecture — that's the same reason Sony's PlayStation 4 won't be able to support PlayStation 3 games. Sony, however, has said that buyers will eventually be able to play older titles through its cloud service. Microsoft will continue to sell the Xbox 360 alongside the Xbox One, but the two consoles won't be able to share games, and their controllers also appear to be incompatible.

Sony and Microsoft bring very different philosophies to their new consoles: the former has pushed its PlayStation 4 into the cloud, while the latter wants the Xbox One to dominate the living room. But Mattrick also denies that this will make the Xbox One less powerful as a gaming machine. "We created something that understands how to be performant for all scenarios and all combinations," he said, describing the company's expansion of its Xbox Live servers.