Nto sure it's too much of an astronomy problem (electric universe excepted!), but I see a lot of it in (whisper it) climate-related conversations in a number of places on the Web. Having a climate-related academic background, I understand the atmospheric physics, the palaeoclimate and recent climate data quite well (as well as my limitations - DK alert!!
). But there are lots of examples out there of people who seem to think that their "common sense", backed up by some pseudoscience from the Intertubes, is enough to trump every national science academy and virtually all the experts in the field. Most of these people have no idea about the science they are trying to dismiss. There is uncertainty ... it's in a range from bad, very bad, to cataclysmically bad impacts, and each year the new research tends towards greater, rather than lesser impacts. So many people really, really don't want to accept the simple, and rather disturbing, reality, and there are plenty of D-K's out there to help them avoid accepting it. I certainly wouldn't tell a dentist how to drill teeth, a doctor how to operate on my heart, an engineer how to build a bridge, or a petroleum geologist how to find oil. I do wish the D-K-afflicted climate skeptics did the same. But lets not turn this into a deleted thread!
Haven't seen much D-K around here to do with astronomy though - everyone is very friendly and humble about their levels of knowledge and their expectations of what they can teach others. That's a great thing, and makes for a great place for beginners in whatever part of astronomy to learn. There's certainly lots for me to learn!
