Whats the deal with Metalcore?

In fairness the only band, althoguh cheesy, predictable, and mmmmmmmm chessy and predictable that plays a killer live show is killswitch engage, ive seen then 4 times and its great to head bang too and generally feel that 4 day stiff neck syndrome thing too., although the crowds at those gigs for what ever reason have shitty 'im out to hurt people on purpose' attitudes which is worthy of a good scalping