>9GAG is Reddit for the 90%.
Content is created in the chaos that is discussion boards (4chan, SA before that). Then it is peer reviewed on aggregators (Reddit, Digg before that), and finally it is distributed to the masses in an easy to read format (9gag, tumblr, FB, etc.)
The problem is the lower the food chain you go the greater the resentment you see people have. People on reddit hate 9gag, people on reddit.com/new hate redditors that only view the front page, people on 4chan hate redditors for copying (or stealing) their memes. And everyone hates that the original message/humor gets lost or diluted each time to goes up a level.
Now you may not think that's a problem, but people on 4chan sure as hell don't want to see 9gag succeed, and the people who create the most content also create the most mischief.