It's a tiresome discussion. Why do we always bring up CEO compensations, but never Hollywood actors', professional athletes' or even painters' (or art traders' - https://en.wikipedia.org/wiki/No._5,_1948)?
Salaries don't need outside validation by people why have no idea what the job involves, but try to assign some "value" to it anyway. It's a free market and CEOs don't get hired if they have outrageous demands and there are better candidates available.