Flaming is still continued because it's effective if applied correctly. Consider if a new user comes into the forums and asks a question that has been answered a hogjillion times.
Would you flame them right away? Of course not. Simply tell them the answer and point them to the FAQ of whatever knowledge-base that addresses new users questions.
What about a second or third time the same user asks a question that has already been answered in the aformentioned FAQ or knowledge-base? At what point do you stop spoon-feeding the newbie and make him read the damn docs?
[newbie] How do you open a terminal?
[Board Vet] It's in the FAQ that I pointed you to about two weeks ago. Go read that.
[newbie] But I'm a complete retard who can barely tie my own shoes.
[Board Vet] Why you little *&^%$#@!
This is where flaming comes into play. After a good verbal dressing down the guy will either go bottle-feed off of some other forums or learn to read for himself.
You have to consider that you're not gonna get one uninformed person a day asking these questions, but quite possibly hundreds. When DSL get's so large that nothing new is being discussed, just the rehashing of the same old questions over and over, you'll wish that more tough love was shown in the beginning by making people find the easy answers themselves.