Union bashing is an easy way out. I was once a Teamster, while working in Alaska. I hated the Teamsters, they hated me, and, I was once a Steelworker in NYC, I hated the Steelworkers Union in NYC, and they hated me. In the 1970's it was clear they had served their purpose in life and were manipulating the workers to keep their power.
When I started working in management, I learned that for the most part, company managers were stupid fucks in the dark days of Union organizing, and they are stupid fucks today. Unions came about because management was dimwitted, greedy, selfish, and, did I say "dimwitted" yet? The fact that they still exist is testament to the fact that corporate management in the US is still dimwitted. Still greedy and still selfish.
Unions derive their power by exploiting the stupidity, greediness and selfishnesh of American corporate management. At the moment, and for significant decades past, they do little of value for the American worker and focus on keeping their power instead of serving their dues paying Union members. But, they exist because management can't figure them out and lets them continue to exist by stepping in prepared and strategically placed piles of shit, virtually at the will of the Unions. Management is predictable and non-innovative and lazy. Oh yeah, and lazy. So they let Union officers outsmart and out hustle them. Not entirely a Union problem, QBN. And based on what I have seen, if Unions disappeared tomorrow, the sweatshop, abusive practices that spawned Unions would reappear the day after tomorrow. So, shitty management spawned Unions, and more shitty management keeps them alive. Upgrade management and Unions will slowly die out.
"Management" is not a government entity. It's a company-by-company issue. There's lots of cannibalism and homogeny in any given industry, I'll freely admit, but to say that unions are today necessitated by "management" is like saying there's a "man" assigned to holding every African-American in the country back from being successful. There are LOTS of reasons that GM, Ford, and Chrysler are sucking wind through their assholes and batting their eyelashes at Uncle Sam since the bailout checkbook came out of the drawer. They're run by idiots. The onerous rules and bureaucracy that unions put in place does, however, make it far more advantageous not to have them around. "I can't do THAT job, someone else has to...so we'll all wait while that guy finishes his break before we move forward, and you can't call him back from his break early or else he'll file a grievance and you'll have to spend hours and hours on that, and you can't do it yourself or we'll file a grievance for that too." Fuck. You.
Incidentally, your statement in bold requires surprisingly little effort to disprove. Just look at the burgeoning automobile industry developing in the southern US (Alabama for example). Ask around about the presence of unions.
When demand for employees outpaces supply, unions serve no purpose. Sure, the economy is bad, but nothing like post-depression America when Unions protected workers against exploitation rather than creating artificial obstacles to the success, efficiency, and competitiveness of an organization.