It's quite easy to explain. Republicans have retreated into their own media bubble, where they can mold their own reality based on "alternative facts". Their end goal is to project their reality onto the world and give it substance. In this bubble world, Donald Trump is the Alpha Male, and JD Vance is the everyman who speaks for the people.
Outside this bubble, though, Trump is a narcissist and criminal, and JD Vance is severely out of touch. The only way to penetrate this bubble is to shove the truth through it until it pops. Sometimes, calling things as they are doesn't get through the bubble, because it immediately puts people on the defensive about their choices. But call them weird? They might agree something a little weird is going on, and that might be just the opening to stick the truth in there.