What 4K? LOL
Dude to play in 4K you nee to have 980 TI that alone costs as much as 2 consoles. How did you expect a consoles that came out 2 years ago to come with a GPU that is as large as half the console and cost 2 times as much? That's not even remotely realistic.
Steam collects data on all users and publishes it for free
http://store.steampowered.com/hwsurvey
People who have Steam are gamers and tend to have by far better tech gear than regular people, of these people less that 1% play games on 4K displays. Look under Primary Display Resolution, it's 0.06%, PCs just now firmly adopting 1080P.
Let's say somehow magically 2 years ago Microsoft stuffed two nVidia Titans (that cost $1,000 each) into the Xbox well 4K TVs make up like 6%-10% of TV sales, so chances are if you have a console that can run 4K your TV can not display that.
4K gaming is a pipedream because vast majority of people will not pay $500+ for a GPU and $500 for a monitor. 4K will take off once you can buy a $200 GPU and a $200 monitor, that will take probably 4-5 years..............just in time for new consoles.
There's a huge difference between being able to do something on a PC as a big cost to being able to do something in a small form factor at $300+ price.