Many present unionized pilots in the US forget that whether they started as pilots in a military plane or a regional Metroliner, Jetstream, Shorts etc, a great many flew for a while with no union on the property, and had no true comprehension of the issues.
I can't speak for others, but often it is hindsight which allows us the leisure to decide whether we should have organized (often at the risk of being fired/failed on checkrides...), or not. Many of us were hired by really small regionals (4-6 planes) which were not very solvent-we were the last to know, once airports began to seize starter units, hesitate refueling planes etc. When fairly new and still young in the business, we were often too conservative, naiive or both to have even considered "rocking the boat"- risking the rath of a chief pilot or the company "president".