I believe the premise of a union in face value is a good thing, but to tell the truth the unions did not do themselves any good over the years with corrupt practices and failing to recognize things outside of their respective bubble. I do not claim to know about all unions so there may be unions that do not fall in what I just laid out, but a decent amount do/have.
Like brother skuder intimated to if there was a concerted effort to address the shortcomings then unions can once again be a force to be reckoned with. Just my take on things.