I'm always annoyed with people who don't know anything about genres. Heavy metal is Van Halen and Metallica. I'm guessing you're all thinking of Bring me the horizon and asking alexandria as "Heavy Metal". NO! That is metalcore, that's very different. You disagree? Well, think of it this way. What if I call Flo Rida "Dubstep". That isn't correct, Flo Rida is Hip Hop.
P.S. I listen to metalcore and a bit of dubstep. I can easily say that as much as I like both, neither one is very musical.