Yet another problem is the common willful conflation of simply being wrong with bad faith or disingenuity. People generally won't correct themselves if they know they're going to get screamed at or dogpiled either way.
That's a lesser problem, because people who get something wrong once are typically fine with being corrected, and contrariwise people are unlikely to dogpile someone for making a single mistake.
Examples of disingenuity include people asking naive-seeming questions to which those same people have already received detailed answers in the past, or repeating factual assertions that they made previously and which were shown and acknowledged to be false. It's not so common on HN but sadly very common on big social media sites or on news commenting platforms like disqus.
