Koller is one of those really bad spin doctors you thought Sony laid off but haven't. I'm pretty sure he once said PSP was experiencing year over year growth in North America ... in 2010. Ignore what that man says.
Back to Syphon Filter, supposedly Garvin once said even Resistance: Retribution outsold the PSP iterations of SF. That's not say Resistance: Retribution is a bad game (because it's not, and it did some things online wise that we've yet to see anyone attempt to do on Vita) but it's pretty sad to see their own IP be outsold by Insomniac's generic shooter franchise.
And yeah, I agree that SCE should've forced Naughty Dog to make a Vita game. What Oscar has been saying (the small team dedicated towards handheld development while a big team works on console games) is what Media Molecule is doing right now. Tearaway is being developed by a smaller team within that studio while the rest are presumably working on a new IP for PS4. But Media Molecule wasn't forced to do that do, from what the people there said they wanted to make a handheld game, and it seems SCE's big studios will only work on a handheld title if they want to ...