I observe this topic for years now and also for me (working as a 3d Artist) the way alpha masks are edited is a kill argument. having Photo installed but basically never used besides panorama work. It is just sad to see a so capable program laying around on the harddrive because (and I have to put it that way) the deveolpers are to stubborn to implement a simple solution to this (by just make the alpha and chanels a normal work area and enable copy and paste). It remembers me of blender when developers and a fair amount of users said that the right click paradigm (and the UI) is fantastic and the world should adjust to that. then two years later they changed it and boy look how the userbase of blender developed. shure, compared to that, changing alpha handling will make a smaller impression, but there are a hell of a lot of artists out there that mainly do 3d visuals and games.
best regards
Jops