Whoever designed the PSP without a second analog stick doomed the system. It is only successful because kids want it and some adults like its flexibility, but, it is a FAILURE because it cannot reproduce the control scheme of games it is designed to mimic in graphical quality.
Face Buttons =/= analog stick. That's putting it perfectly.
You could easily have multiplayer Counterstrike, Rainbow 6 and whatever else with high playability if the system had two analog sticks. Right now, all PSP is good for is 3Rd person fighting games or 2D fighters.