I think his point is that not every metal band has to sound like it was recorded by Adam D and I agree completely. It gets kinda old when Unearth, Killswitch and PWD all sound like the same damn band right down to their spoken breakdowns, reverse tom reverb, and of course the obligatory slow metal "ballad".
I mean, these bands already sound so much alike already, what sense does it make to have the same damn guy record their albums too? Don't get me wrong, the guy is skilled-- I think I'm just bored of his sound.