Today people with stupid ideas are the ones who get most practice in rhetorics. And practice makes you good.
As a result you find very specific kinds of stupid. If you know Nassim Talebs IYI (intellectual yet idiot) there exist supermutants of that phenomenon. For example I just argued with self proclaimed Marxist who managed to have opinions of fascists straight from 40's. He had absolutely delusional view of multitude of things like not believing in industrial revolution, or that machines could outproduce people when making bulk materials. Yet he could muster huge array of minutiae from history, usually correct and supporting whatever weird point he was making. This dude actually was rhetorically decent and very passionate about.. I don't really know what.
Such individuals are far from stupid despite their stupid ideas and they seem to be able to shut down intelligent discussion on niche boards. Specifically because nothing seems to stick: they are not trolls, not really malevolent, not really belonging to any definite camp. Just really twisted, bored and eager to engage others.