He probably did get screwed over by his union, it happens often enough. He has a legitimate gripe and nothing you say is going to convince him that he doesn't. After all, the union is the best, sometimes the only, protection a working hard hat has for wages, benefits and conditions. And we all hate to see another union member who really doesn't like the union.
Every union is made of an upstairs and a downstairs.
In the Carpenters' Union, the downstairs union would be every one who does actual carpenter work, from apprentices to stewards, including retirees. You know, the ones with the calluses. If they don't do carpenter work, they are in the upstairs union. Out of a twenty-dollar loan or a temporary job, maybe, but not in the way they were complaining about just a moment ago. Perhaps because they have other things on their minds, perhaps because they have their own world to worry about - and it is not the same world as the working hard hat's world.