True, it's a form of false dichotomy, but I think this specific instance is particularly interesting in that it allows the holder to dehumanise their opponent to an extent, and justify lack of discussion. It's also an incredibly common conclusion in politics after people gain a somewhat superficial understanding of both sides. I wonder if it might play a key role in social polarization.
For me the strongest arguments are the ones that can argue the opponent's side as effectively as the opponent, and then show why it's weak. And that feels entirely incompatible with a dumb-or-evil argument.