The general intellectual culture also allows people to dismiss those who do know what they're talking about as entrenched ideologues as well. It's a very post-modernist way of thinking.Actually, I think most people are interested in learning when presented with ideas in an interesting and fair way. Too much debate these days takes place via memes and sound bites, and is lead by people with entrenched positions they do not want to examine. It doesn't help ordinary people, nor does the sad state of news reporting and documentary television in the US.
It's entirely possible to actually know something by studying it, but people who have that authority are dismissed as ivory-tower elites who don't know what it's like in the "real world". This of course neglects that those people have studied far more of the real world than those who go off of limited personal perspective.