But it becomes different when a wrong answer got "confirmed" by XP points. Let's don't say that XP point is nothing, it is something. Lots of learners will judge the merit of the answers base on XP points.
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.
For example, in that ugly thread about Oracle. I trust that most of the monks here, including myself, never used Oracle, as it is not free. So at least keep quiet. With a DB like Oracle, even if you have worked as a application programmer, you still don't know much about the DB...
XP points is related in a way. Without XP point, people will be less eager to provide answers (unless they really have answers). Willing to provide answer is different from eager to provide.