I don't see how we can make any argument (directly) that players wages are wrong or excessive. Our society isn't based on people getting paid what they are worth, if it was nurses would be on £50k a week and footballers would be on about £50k a year.
The only way to control it is to have penalties for financial mismanagement built into our leagues. No club should be allowed to regularly operate at a loss and be propped up by gifts from its owner. If they need loans then fine, negotiate them with a bank at commercial business rates of interest.
Maybe the financial fair play rules will help with this, but obviously they are designed with the current state of the game in mind, so I doubt they will actually reduce salaries very much.