This basically boils down to advertising. And yes, Sony dropped the ball with advertising Sly. Just like they did with Twisted Metal too; but I'm pretty sure that wouldn't have sold as well on a Nintendo platform even with advertising.
At least Sony have been pushing hard with The Last of Us recently, which was reassuring to me because it least it shows me that they do still know that advertising is important (I was beginning to think they had forgotten).
Sly just came out at the wrong time. If it had released, as they intended, in the holidays 2012; then it would've been included in the advertising push they had with LittleBigPlanet Karting & PlayStation All-Stars, which would probably have helped.
I'd hope that at least Sly & Ratchet have a future on Sony hardware. Given that Knack is a launch title for PS4, I'd say there isn't too much to worry about for the time being.
