Practically, with the low interest rates, cash isn't worth a whole lot to an average Fortune 500. You can already see how Apple is getting heat for having so much cash on hand, only reason there isn't more is that people are hoping for a tax repatriation holiday. With most large companies being a) well capitalized already and b) able to borrow large amounts cheaply, you have to make a really hard case that holding onto cash (or spending it internally) is the best thing to do.
Funneling all profits back to the shareholders is only a duty when there isn't much else to do with the cash, which is mostly what's happening.
Profit is a financial benefit that is realized when the amount of revenue gained from a business activity exceeds the expenses, costs and taxes needed to sustain the activity. Any profit that is gained goes to the business's owners, who may or may not decide to spend it on the business.
Excuse me but I'm just citing an article that quotes a bunch of CEOs about what they would do with that tax cut.
I suppose they could also retain those profits and expand. But they didn't say that. They said they'd forward those profits to their investors. Not sure where you get a myth out of that.
When is the myth that a company's fiduciary duty to its shareholders includes funnelling all profits back to them going to die?