Of the problems you list, one is false ("no games") and the rest doesn't matter for most people.
Backwards compatibility: kinda agree here but most people don't care about playing the older games, the majority just moves on to new stuff. Sony could be doing better at adding support to PSP and PSOne games to Vita, yes, but it probably doesn't give them enough profit to keep at it, so they don't. Which further proves the point: people aren't buying the old games emulated to justify adding more...
Not a "pocket PS3": being more powerful wouldn't help the Vita at all. It's powerful enough and it is being beaten by a MUCH weaker portable.
Fragile screen? Never noticed this, my Vita is almost 2 years old and not a single scratch on it, and yes I play it a lot (a big chunk of my PSN trophies are from Vita).
