Sunn O))), Mastodon, and Baroness are all bands that non-metal people seem to like. I don't understand why non-metal people like them but I've never liked this kinds of bands. There's probably something that bands like this do that appeals to non-metal people that simultaneously irks me. I don't know exactly what it is but something bugs me about these bands.
I also don't like when non-metal people act like they have discovered in bands like this the truly good parts about the otherwise horrible genre of metal, and that it's only close-minded elitists and fanboys that are keeping Mastodon et al. from reaching the heights of metal fandom. It's fine and good when a band can have a wide appeal, but metal should be for metal fans and judged on those standards, not to the tastes of hipsters and main stream media reviewers.