Man stuff like this is dumb. I personally have an aversion to most things with 'metal' in the title.
I don't think of Earth Crisis, Integ, or Converge as metalcore. They defo have a metal influence, but metalcore to me is an umbrella term for stuff I don't like. When things stop being hardcore. I mean, Leeway & Cro-Mags have a metal influence but I wouldn't call them metalcore. The stuff I'm not into is what sounds like watered down mid 90's hardcore, lacking all urgency just another sound that rock bands play. There isn't anything exciting about it. Now take some Bulldoze, Shattered Realm, NJ Bloodline, Mushmouth/Out To Win, Fury Of Five, Morning Again, Damnation AD, Indecision, Two By Four, Stigmata, Merauder, Irate, Red Eyed Devil... if you call that metalcore then I guess I like a bit of it but I don't like any of the bands mentioned at the top.