Billy Joel said this about country music in 1995:
Garth Brooks is a very popular Country-Western Music singer. It's not so much the pure country music anymore".
It's 2015 and we still hear this all the time, 'that's not even country music'. Point is, that Billy Joel made an observation 20 years ago that music evolves, even country music and when people hear a more contemporary song that they think doesn't fit the mold, they say exactly what Billy did.
During a Q+A with Billy Joel in Germany in 2015 someone asked Joel about Garth covering a couple of his songs like 'Shameless', even going as far as referring him as Garth Crooks. Joel's response may rub country-music fans the wrong way, as he even references when he thought it was "kinda dumb" and mocks it out on his piano, but ends up talking complementing people like Ray Charles + Garth Brooks who have helped evolve and make country music better!

There can't be any hard feelings, though. Both Joel + Brooks teamed up to perform the song that Brooks' made famous in New York City in 2011.

Brooks' wrote on the inside of his album 'Ropin' The Wind' a process of getting to cut 'Shameless':

His people sent us a letter acknowledging that he knew who I was and was very honored that I was cutting it. That was quite a compliment for me then, as it is now. My hope is that Billy, as writer, hears this cut and says, "Yeah, man, the guy's got balls."