Because here in America, we often like to compare dick sizes. Someone having to admit that the console that they bought is simply less powerful than a console they could have gotten for the same price is something that we can't imagine saying. Even if Xbox does have the best FPSs, people don't want to play it on an inferior console.
P.S.: Currently, I only own a Wii U. I WILL own an Xbox One by the end of the year and I will NEVER own a PS4. But the PS4 is more powerful and that is why it sells so well here. If the Xbox One was proven to be more powerful, there is no way that it wouldn't be selling better than the PS4 in the U.S..
I bet the Wii U would sell more than 15M LTD by the end of 2015. He bet it would sell less. I lost.









