Microsoft trailing Sony has proven to be excellent for consumer choice. Falling behind is the reason why they've shed their DRM policies, dropped Kinect as pack in, done game bundles and the holiday price cut. If we had some magical sales parity, they wouldn't have. So, Sony being out ahead is actually creating a better deal for consumers to choose from as Microsoft has to try and catch up. That's how competition works.
This is what so many posters on here don't get. Competition is never about "having sales parity." Never has been, & never will be as long as I've been gaming. It didn't happen on the 3rd generation, the 4th generation, the 5th generation, the 6th generation, or this generation that's happening now.
A company isn't going to have their platforms succeed each & every time.