A lot of those franchises were just on natural declines. I mean Tekken 6? How many franchises don't slow down by the 6th instalment? LOL.
Final Fantasy XIII would've declined from previous FFs even if it was PS3 only, the franchise is just tired and that was an uninspired entry.
If exclusivity on Playstation platforms is some kind of magical factor for success, then Sony should have been able to create a 1st party IP bigger than Halo the last 10+ years but they haven't been able to.