Alright. Hopefully this shows you what I mean. Here we have the tablature view of a guitar:
E ----------------------------------------------------------------
B ----------------------------------------------------------------
G ----------------------------------------------------------------
D ----------------------------------------------------------------
A ----------------------------------------------------------------
E ----------------------------------------------------------------
The guitars Anthrax uses may have a different tuning, but I'm not looking it up as it's irrelevant to my argument. Anyways, most of their songs start with this basis:
E ----------------------------------------------------------------
B ----------------------------------------------------------------
G ----------------------------------------------------------------
D ----------------------------------------------------------------
A ----------------------------------------------------------------
E --0---0---0---0---0---0---0---0---0---0---0---0---0---0---0---0-
and then they try to "switch it up" by adding different notes like so:
E ----------------------------------------------------------------
B ----------------------------------------------------------------
G ----------------------------------------------------------------
D ----------------------------------------------------------------
A ----------7-----------5-----------3-----------2-----------------
E --0---0-------0---0-------0---0-------0---0-------0---2---3---2-
and build their entire song around that. This is what makes most of their songs sound so similar. Keep in mind most bands these days follow their conventions to write their songs. I love Death Cab For Cutie, but there's no denying that I Will Follow You Into The Dark and Soul Meets Body use the same exact chords. I also love Dragonforce, and though I agree with you that their songs sound similar, it doesn't make me enjoy the music any less. My point is, I feel that saying a band's songs sound the same is a terrible excuse to not listen to them, as most bands write songs that sounds similar to one another.