I don't understand unions. If they don't like certain behaviors that are legal like selling to government or paying high salaries, why are they working there in the first place? Just quit. Different people like different things, so go work somewhere that suits you.
The point of unions is that individual workers can be easily screwed over with no repercussions for the company because of the power differential between companies and their workers. Unions seek to level the field a little bit by giving the workers collective bargaining power which allows them to secure better pay/benefits/influence the direction the company is going. When they work it is a very rational arrangement…
In the US the minimum wage haven't moved in decades, at least not significantly. Denmark doesn't even have a minimum wage, yet people are better paid, that's due the Danish unions. Interestingly the Danish unions are actually oppose a minimum wage, because they believe it makes it easier to legally pay people less.