The problem isn't unions good/bad, business good/bad or government good/bad. Its simpler than that. I know it sounds trite but the old adage is true, "power corrupts." Whatever the power, union, big business or government, it will become corrupt and ultimately only interested in its own growth and expansion. I think we know that and try to balance power with power. So you have big business that we balance with unions and government. But what eventually happens is these centers of power start working together to advance common agendas. The net result in any case is, we get screwed.
If you read Robert Bellah's "The Good Society", he argues that we need a strong "civil society" to offset the powers in economic realm and the political realm.
Unfortunately we just argue back and forth in the political realm as if there lies the solution to our problems.