You're doing the right thing. If they don't like your work, nobody's forcing them to read it, and they shouldn't let the screen door hit their bums on the way out.

There's no point engaging with them. To paraphrase Proverbs, arguing with someone like that is just a waste of time. As Mark Twain said, "Never try to teach a pig to sing. It wastes your time, and annoys the pig."

And as Ricky Nelson said, "you can't please everybody so you've got to please yourself."