For example, I have the vague feeling that study music is, in some way, selfish. I know you can say that a society without music would be a mistake, so the society need musicians to do it. But we have to consider that there are lot. but A LOT of music of every kind, and maybe in a near future we wouldn't be able to compose anything new. So studying music would be just to satisfy a "need to learn" by the amateur musician, and the spent money is only for the student and not for the society.
But this is only a thought, maybe I change my mind finding another argument. Anyway, I won't stop in my career. :P