"Anecdotes are easy to find on both sides. But ask yourself which is more likely -- that investors are dumb and managers are smart and investors should just trust managers to do the right thing? Or that investors are smart and need to hold managers accountable because it's the investors' own money at stake, while managers are smart too but always want a longer leash to do their own thing regardless of whether it's good for the company as a whole (e.g. spend more resources on cool side projects)?"

Given that most equity investors no longer make investment decisions and instead blindly buy indexes, there is an enormous opportunity for managers to make decisions that benefit them to the detriment of the investors.