Working in Iceland gave me a weird close-up perspective of unions in a somewhat different context. Icelanders and other Europeans are free to choose whether or not to be in a union (at least in my industry, which is very broadly labelled "office workers"). However, non-European foreigners are required to get the "opinion" of a union on the work visa form, and of course the union won't provide an opinion unless you're a member, thus you're forced to join (and stay on good terms with, if you want your work visa re-application approved) a union.

Despite this blatant extortion, I really have nothing else against the union. Their cut is quite small and they provide services and subsidies you can get your money back through (not that I've ever taken advantage of because everything's in Icelandic, but still...)

But on the other hand, I was almost forced to stop working and subsist on the peanuts the union pays because of a strike that had nothing at all to do with my own working conditions or even those of my co-workers or even people in the same industry (one of the side effects of unionizing in such a small population is the union sphere of influence is quite broad).

So from my experience, I think you've hit it on the nose.