I have to go somewhere. But, imo, the question is simply. Can society set a bottom limit on what price a certain market can value something at, such as labor?
I would argue that what we saw with GM and the UAW in the late 70s was that unions could force a corporation to set the price of labor too high for the corporations to sell a product at a profit.
But at the same time, we also saw a management that could not design a product that could successfully compete with Toyota, so blaming labor for GM's demise would be overly simplistic. But now, GM is union owned, so labor's price is set more by market forces. Yet, GM is outsourcing jobs to non-union countries.