Although I don't agree with your reasoning, I do think it would have a tougher time reaching the base. Mainly for the reason of the series kinda fading away due to a long nonexistence in the public eye. I mean Ratchet is still big at the Sony camp which is why a new one on PS3 could easily be a big game. But Sly has not one that has had its brand to be continually heightened which puts it into darkness. Sure there would be a good amount of long time gamers who would look into it and purchase it but mainstream wouldn't follow suit immediately.
It still has the potential to be big but once again it would be needed to advertised like an entirely new IP because that's essentially what you'll be left with.
Essentially I don't think it has anything to do with the userbase on PS3 just that the brand has kinda faded due to lack of inactivity.
