Lots of other genres besides metal are skipped over by the grammies. Awards shows...are all about country and pop
And I live in Nashville....immediately your mind goes to honky tonks and country music, right? I think more folks here in Nashville proper listen to R&B and Rap and Latin music than anything. You have to really get down into Franklin and Brentwood to the "richer" folks before you start hearing Country as a sole preference
It is all about shameless promotion and ego stroking, as was mentioned before. No sense getting all upset about it....just stop watching. I know I don't.