Short version: Cuz it sucks.HydroFire said:"Fuck xbone ps4 FTW" gives no explanation at all to why the xbox one sucks.
Why does it? It's fixed all the DRM that was actually going to be good. Like steam.
Long version: On its own, the Xbox One isn't a bad system, now that they've removed the most glaring of its issues. Matter of fact, if they'd remove the ridiculous Live Gold paywall between the user and 98% of the internet content, I would go so far as to call it pretty damn good on its own.
Unfortunately, it's not on its own. It has to compete. And it's primary competition is not only priced $100 less (supposedly because it doesn't force the user to also purchase a hardware addon that nobody asked for), but also performs better according to every report out there.
By every objective measure, it's an inferior console. The only way it could potentially be superior is in the game lineup, and that's very much a subjective thing. Personally, I'm a bit more interested in the Xbone's exclusive lineup, but it's not $100 extra interested.