It isn't the DF community from my experience. There has always been good and bad people online. The bad were a minority, that is changing.
In the early days of gaming the gamer was in all essence an outcast. This made the gamer value friendship more. Gamer's by nature like to be challenged and games tended to be less forgiving.
If you were an early gamer you will remember having to replay levels over and over because saves points didn't exist, It would take you time to work through some of the harder games, if you had gamer friends you would share info on games, always working together and only against each other when playing VS mode. You didn't have the internet full of guides to tell you how everything was done, so you had to work at it if you wanted to complete your favorite games.

Then the internet hit. Gamers were still very much in the minority, you didn't have to rely on friends to get/share that info due to page upon page of easily to find information.
As time went on needing to be friendly became much less important, online games like first person shooters became very popular and it was all about being the best among the people you played with.
MMO's still had that need of friends to complete content but even then the attitudes were beginning to change. You had to be a member of a small community and everyone else didn't matter. Some people would only be nice as long as they were getting that item/help they needed, when that river of help ran dry they would move onto the next river.

Now games are mainstream people are competing to be considered the best at everything. Firsts etc . Now as games began to change to need less time to fit in with the new massive audience the need for other people has become almost 0.
People expect everyone to have read up on everything in game before they get to it because if someone else plays badly it effects THEM, they have no concern for anyone else.

Obviously there are still many people out there like myself who like to play for fun and want to play the whole game. Unfortunately we are now the minority.