That's not the point though, hate that argument. Graphics CAN make a game better and the proof is that if you have two games that are the EXACT SAME except one has superior graphics you'd choose the one with better graphics every time. They can also add a ton more immersion which more immersion makes games better as well.
"Do" the automatically make games better...no. "Can" they make games better...yes!
Sorry I'm in a ranty mood today, kids got up early and are being a bit unruly this morning.
"You shouldn't be asking HOW things are, given that we already know there is something..but rather WHY things are, as opposed to there being nothing."
The thing is, it's such a silly request. It's technically capable of producing the (no doubt more impressive) visuals we'll see it pushing in 2016. Just because it's capable doesn't mean it's happening.