Dismissing factual criticism as “insulting” is an avoidance tactic, and on a pretty juvenile level at that. It’s just true, and there’s no way to get it through in a sufficiently groveling way. *That avoidance *is “doing the GOP’s work for them”, as a wise man just said.
To repeat, it’s time for the purity ponies to quit sulking and take on some actual responsibility. If you disagree, you’re not explaining why, you’re simply complaining about tone of voice.
ETA: I do note that you’re complaining that the Democratic mainstream lost to Trump, which is fair, but you’re stopping well short of saying what they should have done instead.