M.Shadows has explained why Avenged Sevendfold initially turned down the chance to open for Metallica. During a recent interview, he said that the band didn't think it was a good idea because “if you headline, people think of you as a headliner, and if you go and open for people constantly, they'll always think of you as second fiddle.”
He explained, “We have only headlined for so long. And one of the things that we heard early in our career, and one thing we respected immensely about certain bands, is if you headline, people think of you as a headliner, and if you go and open for people constantly, they'll always think of you as second fiddle. So the idea of opening and taking all the toys away, everything everyone had ever seen — my question was, 'I don't think this is the right look for new people getting into Avenged Sevenfold. This isn't where we're at.'”
She continued, “But to a lot of mainstream people, it was, 'Oh, you're the band that opened for METALLICA,' which put us on a higher pedestal, which was weird to me. And so the conversation just went, 'We're not gonna do that.'
He added, “Then they would call our agent and offer more money, and we were, like, 'We're not gonna do that.' Then it eventually became, like, 'Okay, we're gonna do that because we'd be idiots not to.' But I still walked away from that tour extremely grateful but extremely, I think, right about taking that tour. It did put us in that weird position of, 'You're second fiddle to this.'”