"Outrageously exhorbitant exectutive salaries" don't need to be justified to anyone - what they get paid isn't anyone's business. None the less, its worth pointing out that their salaries are decided by the same people who have the most to lose if they don't perform well.

The same principle does apply to the lower end of the wage range. Employers generally give raises and promote their top performers because it isn't profitable to lose them to another employer who wants to take advantage of their skills. Those "overpaid" executives didn't likely start out as CEOs or whatever, they began somewhere far down the wage scale, and proved their worth over time.