In this context I don't really see a difference between "stop making your point about the subject we've been communicating about" and "stop communicating in general." Am I supposed to talk about the weather, or engage in a lengthy meta-discussion about talking about the subject we've been talking about?

I never used the term idiots, that's you putting someone else's words in my mouth.

It's hard for me to imagine how a person can make a mistake in a given domain without being at least bit incompetent in it, hence my point about competence/incompetence existing on a continuum.

Edit: ...and if the person were malicious, it wouldn't be a mistake to begin with.