Prototype Veteran: Why is it only A-Wing
The card is supposed to improve A-Wings. No other ships.
and why do you only need to have a PS greater than 1
Prototype with the upgrade might be too cheap for what it can do.
Enhanced Scopes: Why isn't this specifically directed at Arvel Crynys who's single biggest problem is that for movement is PS isn't 0. That would very easily and dramatically change him.
Only the game designers can answer the question "why". Thee card is obviously intended to help other ships. Not any A-Wing.