[jusq2]

Intentionally.

Historically if you want to learn something you have to prove you are worthy of being taught. One comment expressing interest in the matter is not enough. This is the route Trump took to his overconfidence in all matters.

There are lots more people who think they are worthy to be taught than people who are. The internet and khan academy isn't going to change that distribution. It's fundamental to nature. Look around at your own families, classrooms and workspaces. Not everyone has the capacity to understand the problem on the blackboard let alone solve it. And such people shouldn't be misled into believing they are contributing when they cant.

I'll leave it to Bruce Lee to sum up - https://www.youtube.com/watch?v=BC7XGATDfAo