Of course it does - no one's arguing otherwise - but Killzone proved even the most staunch pixel counters couldn't even tell the difference between 1920x1080 and HALF that resolution. It's so sad, and yet hilarious at the same time.
I would say you're partially right, in that most people couldn't tell. however, to say it's not important, even in cases like this, is a little shortsighted.
you say it's unimportant because most can't tell, and that's where you're wrong. Most can't tell because there's nothing to compare to. Imagine if KZ was also on pc at true 1080p....are you suggesting that most wouldn't be able to tell the difference between PS4's lowered mp resolution versus the pc version (hypothetically speaking, if there was a pc version)?
So yeah, you ARE CORRECT, it really doesn't matter, nor can most people tell....but they can't tell more because there's nothing to compare it to.