It all comes down to the Developers really,
Xbox is faced with two huge problems(as evident by the net lashings), they have eliminated the ability to buy and trade used games. To me this isn't a huge problem, I have stopped trading and selling my games. For others this is a huge problem and I guess I could understand them.
The other problem is always connected, though this a bigger problem than the first I mentioned I hope it lends itself to some really neat gaming experience.
Developers are the only ones with the power to sway a console war,
If developers chime in on this and decide to put all the exclusive titles on the Xbox One, it may sway the consumers into buying an Xbox ONE. Why would the developers chose the Xbox ONE over PS4? Because they lose money(potential) when someone decides to trade in or buy used games, you might not think these things are too big of a deal to care about but they are.
Smaller game company's struggle with todays market. Its only the big companys that manage to stay afloat.