The simplest answer is that many people believe the "free market wage" is not always the apropriate wage.

Anyhow your defining the free market wage, as the wage the get paid if the have no legal help in there negotations. And then your defining the appropriate wage as the free market wage.

So you are basically stating that by definition the appropriate wage for people to be paid is the wage they could negotiate if they have no laws to help them negotitate.

Basically your conclusion is the axiom you start with.