Things are still pretty close in the US (vs PS4) despite launching at $100 more with the DRM, Kinect, TV and other issues at the reveal... had they been more focused, produced a box that was cheaper with more power, you don't think the Xbox One would be selling more than it has? And if its selling more than there isn't that much room before its selling as much as if not more than the PS4 has.
The 360 was an absolute behemoth in the US compared to the PS3, people switched for a variety of reasons but I think their [MS] screw ups were the significant part of XB1 selling less, whether it was DRM, price or otherwise