>> Very often, people post answers that are wrong

Perhaps you should go to www.everyonehereisperfect.com. In the real world, people make mistakes. Learning is not a process of always getting the right answer, it is a process of gathering information about a subject from right answers, semi-right answers, semi-wrong answers, wrong-answers and everything in between. Sometimes a wrong answer makes an assumption about the problem and just seeing that assumption sheds light on the problem so the wrong answer ends up being helpful. If you can't learn from mistakes (your own and others'), you can't really learn.