Mastodon vocalist and drummer Brann Dailor did an AMA on Reddit recently and was naturally asked about Brent Hinds apparent hatred for metal. It might have been an offhand remark with a few follow ups, but people were pissed at the time and people have not stopped being pissed ever since.
“Brent wasn’t exactly serious about that, he likes metal, but more importantly, he likes what he likes, he likes music, I don’t necessarily put music into genres for myself, I get the same feeling from Slayer that I get from Stevie Wonder. He doesn’t like certain types of metal, he digs the classic stuff, and Melvins, Neurosis, Etc…”
Hinds has been known to be a bit of shit-stirrer, so I don't know how true that was. He says he's been pushing them away from being heavy metal, yet Mastodon consistently and unfalteringly puts out great hard rock and metal records? Not too sure about that… I mean, come on. Even Once More 'Round The Sun was a big-ass rock record for the ages with plenty of heavy bits on there, however you're defining "heavy." The band has moved away from the old sound, but I'm not so sure about all the "fuck metal" nonsense.