According to Ayn Rand, those who are in power keep control over the masses by rewarding mediocrity:
“Kill man’s sense of values. Kill his capacity to recognize greatness or achieve it. Great men can’t be ruled. We don’t want any great men. Don’t deny the conception of greatness. Destroy it from within. The great is the rare, the difficult, the exceptional. Set up standards of achievement open to all, to the least, to the most inept-and you stop the impetus to effort in all men, great or small. You stop all incentive to improvement, to excellence, to perfection… Don’t set out to raze all shrines-you’ll frighten men. Enshrine mediocrity—and the shrines are razed.
I think there’s some truth in there. I don’t think it’s a real secret agenda by those in power, but something that just sort of happened. Look at the majority of movies Hollywood puts out or the stuff that passes for music these days and you can see the enshrining of mediocrity at work. I think society started rewarding mediocrity for profit. If you lower your standards, the talent pool grows larger, which also means more chances to make to money.