The average would or at least could be a rather poor metric, most people could get poorer and the average could still rise. Besides that people certainly care a lot about inequality and, in my opinion, that is absolutely justified. You don't become a billionaire by producing goods worth billions with your own hands, you become one by letting a lot of people work on the factory floors and taking a share from the value they produce. And because you can, you don't take a share that makes you ten times better of than your workers as compensation for the risks you took, you take a share that makes you thousands of times better of.