Well, this one's all about fan voting too. I started my gigging live (I'm a bass player) in the local country music circuit in 1976. We did a lot of Merle, Ray Price, Jones, Hank (the original and best one, not his progeny who get more annoying each generation), etc. I trace the decline of country music to Garth Brooks. Not that Brooks is responsible, but his success was totally responsible. Here's what happened...
In the past Billboard's charts were based ultimately on casual reporting of sales. It was based on people talking to people at stores about what was selling. Some stores did keep accurate records, but many smaller ones were reporting what their impressions of what the top sellers were. The week Billboard switched from self-reporting to using actual point-of-sale receipts reporting the new Metallica record dropped from #1 and the new Garth Brooks album shot from somewhere in the teens (I think) to #1. It got the industry's attention. They followed the dollars and it's lead inexorably to the point that modern country music, at least for the radio and the general public, is really bad '80s pop music with an Oklahoma twang and an out-of-place fiddle or steel guitar tossed into the mix as an afterthought. Witness Jason Aldean as our prime example of this...
Now there's some good stuff, just like any genre- much of it flies below the radar, but some leaks out and influences the upper parts of the charts- I do like Martina McBride and Trisha Yearwood for example, but wouldn't really call either of them "country" in the same sense that Merle Haggard, or even Emmylou Harris is country. And the atrocity of Sugarland (could Jennifer's voice be any MORE annoying?!) lead to the acceptance of Lady Antebellum, so there's an occasional bright spot.
But anything that's hugely successful is successful in large part by appealing to a lower denominator than the more challenging stuff, with few exceptions. Did the Beach Boys ever win a Grammy for their great music? No, only for "Kokomo", because NARAS was ashamed they'd never given a Grammy to them. It was a consolation prize rewarding one of their worst records in atonement for not rewarding them for the huge contributions they'd really made.
John