The process is rather natural: people learn that there's a place where clever guys answer YOUR questions, and they go there to get their task fulfilled. Every place - either on the net or in real life - gets filled with people who are really not very appropriate, and it would have been better if there was none of them.
I also expected to see higher concentration of clever, nice, professional people out here, but like it always does happen - they're rare. Often you can get no gratitude for your help, but it happens everywhere.
Don't take it that serious: you can't the world, so just take from it the things you like and ignore everything else!
Life's short, and it's f***ing ridiculous to spend your precious time on the sulks! ;)