They're under the same category as Suicide Silence. The deathcore that scene kids enjoy. You have other deathcore bands out there like Cannibal Corpse and Job for a Cowboy that scene kids could care less about but WC and SS are fan favorites. I'm assuming it was because they did Warped 2 years ago?
I'm not usually one for arguing about genres, especially when we're talking sub-categories like here, but Job For A Cowboy & Cannical Corpse don't play deathcore. Though stylistically their songs share similarities to SS & WC, they don't contain the same hardcore/metalcore influences that make deathcore songs more dancey/moshy - and that's the element of the songs that lots of "scene" kids (who already listen to Post-Harcore & Metalcore) latch on to. All the bouncy breakdowns & 2 steps make them catchier and easier (or more fun) to listen to than straight death or tech metal or whatever.