Certainly in some technical forums such as electronics, HiFi or computer programming you find there is always the guy who abuses almost everyone for being stupid and having inferior knowledge of the subject. They have the following traits:-
1. They never actually answer questions themselves.
2. They accuse everyone else of technical incompetence.
3. They claim they're too busy to bother with "this stupid forum".
4. They must spend a large part of their 'busy' day posting abuse on the forum they're supposed to be too busy to bother with.
5. No technical knowledge or help ever comes from them.
6. They explain their refusal to give useful advice with "I'm too busy to bother with idiots like you".
So you don't have to be Sherlock Holmes to conclude that they know jack-all, and imagine that smart, useful people would spend all day writing abusive crap.