A wise man once said I've never known a company with a union that didn't ceserve one. We tend to generalize a lot. Unions, like corporations get old and mature. Where corporations tend to achieve what may be referred to as a high maturity quotient; more employees at their level of incompetence than not, unions tend to get seemingly powerful and lose focus on both who pays them and who pays the employees who pay them. The union that leaves striking workers on the picket line until the employer either goes broke or shuts down that particular operation has certainly lost focus on certain realities. Unions can also suffer from the same greed as the hated bankers, greed is greed no matter whose it is.
I have been a member of two unions, and a leader in one of them. It is a common complaint that the union protects the slacker, this is true, but it is also the law. The union also protects the poor schmuck who may have made a mistake and would have otherwise been canned and replaced by someone else who probably would have made the same mistake. Instead, the mistake is used as a training excercise so further occurances may be avoided. The good has to come with the bad, or all we'll get is bad.
Collective bargaining is far better than going at it alone ending up with a hodge podge of mini agreemements. Unions were a solution to a problem, some have just become a problem, but not all of them have, some do actually find ways for the company to save, and even make money.