> They always have the choice to not do the work. You just don't show up and that's it. Not doing something is the easiest thing to do.
In a country where your employer controls your access to healthcare and retirement, as well as indirectly controls your access to these things for the rest of your life via references (future employers will shy away from hiring a lone person who refused to do as they were told and was fired for that reason), I would say this is not easy at all.
IMO, modern companies in America are turning into a sort of benevolent government; and that's why you have all these protests. Cut employers out of things fundamental to life like healthcare and retirement, and turn it into a true monetary exchange. Then you will have far fewer of these protests; and people might feel more comfortable quitting en masse instead.