Yes, people who post wrong answers don't know that fact themselves and didn't mean to cheat others, but at least they know whether they are good at particular areas. ... So at least keep quiet.

Sorry, but discussion is what this Perlmonks is about. Sometimes a wrong answer teaches more than 15 correct answers. If you expect every answer to be spot-on, you've come to the wrong place.

Update: based on the, *ahem*, discussion beneath this post, I thought I should clarify my position a bit. I do not think we should encourage or approve of answers that are either intentionally wrong, purposefully misleading, or woefully uninformed. But that's different from simply incorrect. The former should be condemned, for sure, but the latter should be accepted as a cost of discussion, and dealt with in a constructive way (e.g. explaining why it's wrong).