Oh they absolutely are. and these days, it seems like hardcore fans caim them as ‘theirs’ (Converge, at least).
The other problem with metalcore is that it’s been so horrendously diluted by all the nonsense that’s come out of the Warped tour scene in the last ten years. Every other album I get sent to review is some six-piece band that sounds like a shit(ter) Atreyu, with horribly compressed drum triggers and autotuned choruses. Almost always on Rise Records, too. A world away from, say, At The Gates. It’s basically metal’s “emo” at this point.