One could definitely do that and I think it is a very sensible way to handle things.
A big thing that has kept me from going that route myself though is that I really like the enormous pressure to shoot well imposed by Minor scoring - especially in a Division where Major is allowed. I think I would become a worse shooter if it were suddenly game-profitable for me to shoot A/C on most targets. I think Minor is a lot better influence on me, with USPSA not being my sole focus, but as a means to further overall pistol shooting skill.