They really had a choice. They weren't held down and vaccinated against their wills. Those that quit are the evidence of that. Nobody stalked them, or arrested them, or chloroformed and vaccinated them. And they exercised that choice, some opting for the vaccine, some for other work.
They may be pressured eventually by financial concerns if they will not vaccinate and cannot earn what they were earning in a professional position. Some will do fine, and everybody should be happy - the nurses that don't want a vaccine, and those that don't want to employ one without it.
However, some will feel financial pressure, although they have incurred that themselves with their choice. I'm thinking about the nurse who is a single parent of minor children with a single source of income who was just getting by before a significant drop in income. Such a person might have to give up vacations, braces, private school, eating out, and in some cases, a roof and food for the kids, or relent and take the vaccine. I don't see too many nurses letting that happen to themselves and their families.