Considering the Wii U is 3rd it isn't an amazing achievement either. If you count the 3DS which saw a pokemon release it is somewhat of an achievement. I would however judge the Xone performance by its yoy numbers and growth and not on its place in the console wars. The PS4 did really good though considering it sold over 2 million on BF and might sold another million on CM.

Or there's hardly any other choices but a 4K TV.

That would be a fast transition. Here at least there are still 720p TVs available, but only in the <32" size range. Or at least there used to be until recently. I haven't been out for a TV perv for a while so not sure what the minimum res on small TVs are at the moment. There are certainly still 1080p TVs available in size up to 55".