The problem is that, while I agree with more or less everything you say here - "writing off" approximately half the population is not going to work. You can't do that in a democracy, if only because that approximately-half actually have rather a lot of collective power. If they didn't, it wouldn't be much of a democracy.

My argument here isn't moral. It's that this class of strategy simply cannot be effective. I'm not claiming a better one, only that it's on all of us to look.