That observation is only valid if you ignore all other factors that could differentiate those areas, which is obviously ridiculous.

It also presumes that unionization is the only way to rid yourself of the fear of getting fired. Unionization will alleviate the fear of getting fired based upon factors relating to competence, but another way to do it is simply to increase your competence. I don’t fear getting fired at all, partly because I know I’m competent enough that it’s incredibly unlikely, and partly because I’m competent enough that I know I could simply get another job if I wanted to.