Unions should also support a democratic view, IMO.
I'm all for Unions, was a Union rep myself for many years, back in the 70's. However, they can also be a bullying force in their own way. I grew up in the days of the Steelworks and Miners' strikes. Horrible, horrible things happened in those days, on both sides, a lot from the Unions themselves (Arthur Scargill et al).
OP - you cannot only belong to a Union to protect yourself. Think of all the hardships other people have suffered over the years to get you to this point. You do have to give something back in return, and stand up for your colleagues, at times. Comrades have fought in the past, and still fight now, to protect the beleaguered and downtrodden person. People like you and me!
However - sometimes, the Unions can be a bullying force in their own right (and my family has been on the receiving end of that too). All well and good "fighting for the rights", but that should take into account everyone's viewpoint - the UK is still a democracy, thank goodness, and isn't that part of what a Trade Union is all about?????? Rights and views of ALL people
It is particularly hard to strike if you are in a caring profession, because you have entered that profession as a vocation, and it is very hard, if you know you are letting those people down.
Rock and Hard Place