ANY of these "unions" are really like franchises. When a pilot group joins ALPA or IBT, what they're really getting are access to their resources, I.E., a legal staff experienced in contract negotiations, enforcement, and regulatory matters, engineering resources and expertise that can be used in accident investigations, and of course whatever political connections the organization may have. They provide the tools. But like any other tool, the employee group still has to know how to use them, when to use them, and most importantly of all, be willing to use them as necessary.
What an employee group doesn't get when they join a union is, paradoxically, unity. They may get the tools and resources under which to create and foster unity, but they don't get unity. That's important, because unity is the single most important factor in the success of any labor organization. It is lifeblood of such organizations. Unity cannot be bought, sold, or forced upon a group. It doesn't come from the fact that everybody wears a certain lapel pin or carries their ID badge on the same color lanyard. Unity comes from the hearts of the members. An organization either has it, or they don't.
How DHL/Astar wound up where they are today is a long story of interest to no one. Yes, the economy sucks. Yes, the company could have done more. And yes, ALPA could have done more as well. But if you were to narrow the focus of what went wrong down to just one factor, it could well be that it was the pilots themselves who (unwittingly) played the pivotal role in their own demise. And that would not have been any different regardless of who was representing them.
Just my $.02, and worth exactly what you paid for it.