you're totally free to start a few companies and pay 'fair' salary to the execs you hire
or, if an executive at some publicly-traded company is paid way over his/her value, it would mean that the company is inefficient; subsequently, you may want to invest in the competition, or short this company's stock to exploit this inefficiency
in other words, put your money on the line to prove your argument
No, this is absurd. Their paychecks don't simply rest only in the hands of the executive, but in the hands of the worker as well. I'll concede it's a more valuable position, but not 1000x or 100x or even 10x worth the value of the avg. line worker.
Taking it further, frankly most of the executives I've worked with aren't responsible at all. They're generally sociopaths as well!
The Gervais Principle holds.