Metalcore has always struck me as a bit of a musical tragedy. There is a great deal of actual talent in the genre...but scarcely an original idea in sight(or sound I suppose). They seem to draw upon all the WRONG elements of otherwise exceptional genres(thrash, hardcore, death metal) often eschewing the superior bands altogether as influences. They affect a rough and tumble(if unconvincingly so) image while they croon and wail about their poor wounded hearts and similar effete, emo piffle. They usually have very weighty, heavy production values, though seem to believe that this in and of itself gives the music power - which it does for about three seconds...then the moment passes rapidly. And somehow this whole mess appeals widely to the herd - which is always a sure sign a decadence on parade.
There is definitely some sort of analogy to modern society in general in all that - confused, possessed of great talet with no idea what to do with it, directionless, neurotic, brash and bombmastic for no apparent reason, resentment themes always on display, etc.