Fairness is related to justice, the recognition of people's rights to their own lives.
A free market will create big differences in wealth. That wealth disparity is simply a byproduct of freedom -- vastly diverse individuals competing to serve consumers will arrive at vastly diverse outcomes.
That disparity is not unfair -- if it results from free exchange.
As I show in my new book, "No, They Can't: Why Government Fails -- But Individuals Succeed," the free market (which, sadly, America doesn't have) is fair. It also produces better outcomes. Even "losers" do pretty well.
A more astute observer than Moore might show how unfair government intervention is. Licenses, taxes, regulations and corporate subsidies make it harder for the average worker to start his own business, to go from being a "little guy" to being an independent owner of means of production.