Never heard of “horrocore” before reading this, but looking online I found an interesting write-up: http://www.hipsterrunoff.com/2009/10/horrorcore-is-bad-for-societyhumanity-horrorcore-must-die.html
The article is written in a self-consciously “ironic” way which I usually can’t stand though actually works quite well when dealing with this particular genre. I especially recommend checking out the 15-minute “Juggalo gathering” you-tube clip that’s half-way down or so. If I came across it without any context, I would think this was some brilliant SNL-type parody or something…