This is what happens when 3rd generation /b/ "newfags" get tired of the watery vomit pool that /b/ has become, and they decide to click around for a while.
because of course guro is cool and edgy.
The problem is, when they begin to think they know how to appreciate anime, and they stick to other boards.
The same can be seen occuring in /g/ & /prog/.
It happened in /v/ loooong ago.