As the grandson of an organizer for the garment workers, I have an enduring affection for organized labor, and an unshakable belief that it serves as an irreplaceable counterweight to the exploitative urges of management (way too many historical examples to cite here). That said, I've come to believe that unions have a life cycle all their own. In infancy they emerge as a dynamic, socially powerful force for change and economic justice. With each improvement in the status of their members, each victory, there are gains to be held onto, and their larger social goals diminish. With maturity and continued success for their workers they ossify, and become organizations solely committed to the preservation of the perks and status of their members to the exclusion of any greater social good.
Nowhere is this more visible than in the self destructive choices made by public service workers in the face of unsustainable public pension costs. It's not only lawmakers beholden to union political support who are suicidal, it's the unions themselves. As you are fond of saying, "when something can't continue indefinitely, it won't." Current public expenditures on employees who are no longer working is no exception