The Grammys has never been known for supporting heavy metal. Heavy bands show up and it's like a burnout kid crashing his parents' fancy dinner party. Even when Halestorm won Best Hard Rock/Metal Performance for their song "Love Bites (And So Do I)" at the 2013 Grammys, Lzzy Hale told me that she felt like the band was the awkward red-headed step child the entire night.
Hell, the metal category isn't even a part of the televised ceremony. Regardless of that, the nominees for the the 2014 Grammy Awards have been announced, and rock and metal have a surprisingly solid presence.