How many TVs out there let you see the content of both HDMI ports simultaneously?
My HDTV will let you display picture on picture on a selected HDMI port and the TV tuner, however I actually found it pointless.
When you "snap" the TV view, it shows side by side your game so you can see both at the same time.
Honestly do you really think many people will use this?
Not many do, and if you're waiting for your game to load (xbox or ps4), you can snap and play the other while waiting. Or if you're waiting for your friend to get on and log in, no one said you can't play a quick game on the other port while waiting.
Again do you honestly think many people who own an Xbox-one and/or Xbox360 and/or PS3/4 are going to do this? While I wont comment on the Xbox360 I find my PS3 loads a game in well under a minute (usually 20~30 seconds) and that is not even enough time to play one round of Angry Birds. Not only that but the controllers are totally different so you would play one or the other but both?.
If Sony was smart, they'd put a mode that lets you see your friends on PSN that works well in "snapped" mode so you can monitor your friends list while waiting and playing something else.
Well I have not played the PS4 and not many have so who's to say Sony have not considered doing this although in my case if I am playing a game the last thing I want to do is monitor a friends list.