it is a way to know other people and know yourself, we are lack of communicate in our real life, i guess seldom anyone talk to people in their real life like this. when we start to know others' inside world, we would have less chance to feel confused of our position in society.
If I have a question I usually look for the answer myself before asking it here. Some people have good questions that promote thought and discussion. If no one asked questions then we couldn't answer them. Neither is better than the other. I don't like dumb questions or dumb answers though.