On the PS3, there are literally hundreds if not thousands of games.
Out of all of those games, do you really expect people to see Dust 514 with no adverts?

Now, use your brain for this one, what happens with a new console, with only 5-10 games?
People get bored from those and then what?
Oh wait, look at that, a free to play shooter on the PS4...
I am getting kind of bored from Killzone Shadow Fall and Blacklight, let me see this...
Hmm... This game sounds interesting...
And there you have it, a new Dust 514 player.

Also, PS4 sold a million units on day one, Dust at best has 30k active players that login daily.



Now would be the perfect time to release Dust 514 on the PS4, where exposure would be the highest.



Note:
No, I'm not pushing for a PS4 version, I'm just debunking the idea that because there are 80 million PS3's the game will do here better than on the PS4.

That is true.
But even with the bad exposure and a at best mediocre game got 30k players, it can't do any worse on the PS4, it could even do better.