Maximum wage doesn't make a lot of sense. Think of it this way:
In order for a company to benefit from an employee, the employee must (overall) add more value to the process than they receive in compensation. So, for example, a worker making $20k gross yearly should add . . . I don't know, $30000-$40000 or more to the process to justify them working there. Of course, in real dollars, it costs far more to employ a $20k employee. You have payroll taxes, training costs, mandatory health insurance options, etc. So maybe the $20k employee costs $30-$40k just to employ, meaning they need to bring in $50k or more of value during the course of a year's work to be "worth it" for the employer. Otherwise, there's no purpose in making the hire. It just doesn't work.
Realistically speaking, the same should apply even to executives. If the CEO is also the owner then obviously he's going to walk off with all the profits. But the CEO of a publicly-traded company with a board of shareholders is not in that position. So if a CEO wants $10 mil annually in total compensation, then he should somehow bring more - much more - than $10 mil in value to the company. Can any CEO really justify that? By what metric does one make that determination? Hard to say.
But if someone came in and brought the company tens of millions in profits with some brilliant new idea or strategy, then yeah, it isn't outside the realm of the reasonable to assume that said someone deserves an eight figure salary, at least for that one year.