I am not saying the IBT or 1224 is perfect, but, I have always though it came down to who would support a group during a time of labor problems, i.e. a strike. What is ALPA going to do to help you? DAL, etc going to stop flying your freight? Yeah, some guys will come out and walk the line with you, but when the rubber meets the road, if the freight doesn't move, the company loses money...bottom line. At least with the IBT you know your freight will not get put on a truck, moved by a truck, handled by another teamster, flown by any other IBT group, etc. Let's face it, your companies "revenue stream" is a lot closer to the IBT than anything ALPA has their hands near.
My other big gripe with ALPA was that if you weren't with DAL, NWA, USA, or the other legacies, you might as well kiss "fair" representation goodbye. ATI, etc will quickly realize that they are not in that category and do not get the same treatment as everyone else.
I truly hate the union vs. company thing but after 20 years of this, I know it is a necessary evil. Sad really. The flying part of the job is great, it's all the other political BS that really sucks!