The clue is in the word. 'Union'.
We are seriously lucky this country has any left, following concerted political attacks on them by successive Tory governments. The most draconian anti-union legislation in Europe makes it extremely difficult to achieve successful ballots for strike action - requiring over a 50% turnout - so if your members do vote to strike it tells you something about the strength of feeling in your sector.
Unions rely on the basis of collective bargaining. I did vote 'no' to our latest ballot as I believed we were at an impasse, but fellow-members disagreed. THAT is democracy, and I abided by that decision.
There are certain principled reasons for striking or not striking. My organization has a number of people who are non-union members, which is fine and up to them. If you are a member, then crossing a picket line is a no-no (whether or not you're enamored with the incompetence of your General Secretary, but that is another issue).
I would not and have never call anyone a 'scab'; nor have I treated colleagues with anything less than cordiality and professionalism if their political views don't happen to chime with mine. That's called being an adult.
In no way, either, would I support your stance.