The problem is not the managers, or people with MBAs. The problem is that the Delaware chancery courts, where most American corporations are incorporated, long ago ruled that the duty of the Board of Directors is to manage the company to maximize the returns of its shareholders' investments. They can, and frequently do, get sued if they do not do this.
Serious question. Did the quarter system come from the agrarian economy? If not, where did the emphasis on three-month increments come from?
And a lot still is today. Homes, cars, clothing, [specific] food, it's all tired to the season.
In my opinion the race has been run. The damage to our planet is probably irreversible insofar as that at some point human life will not be possible. At that time we can only hope that a more intelligent species will come along and do better than us.
In the Golden and Gilded American Ages, the main shareholder of the wealth-generating American companies was almost always its owner (same person as the chief executive), or his heirs. No MBAs.