There was some mayor devs that decided not to port or develop to for the PSP because it didn't gave profits. This is well documented, just Google a bit.
Killing may be a hyperbole, but it did reduce the potential library of the system.
Explain me then PS2 vs PS3 situation or DS.
look at the PS vita, its not hacked and its dead in the water lol.
Yeah and PS3/360 was at hypest part of console life (when mobile yet didn't hit) and still didn't sell much more games than PS2. DS/Wii was broken from almost start and no one complained.
PSP died simply because there wasn't anymore any puch from big developers to get big games on it. Everyone moved to home consoles. And there wans't indie scene to keep it alive like vita ("life" is here kind of overstatement)
Even now on 3DS you don't see much support aside from nintendo and few minor developers. And ofcourse 3DS is broken (sky3ds, gateaway) for almost all its life and some developers don't mind setting records for their franchizes...