Country music has evolved to the point where two stations can play music from the same era, but skew it male or female just as you do with Rock music.
But that's exactly what's killing rock as a viable radio format! There was a time when rock radio was dominant. Now, it's been niched to death. You got classic rock, you got alternative rock, soft rock, active rock, all kinds of rock. They're targeting the fringes and each gets a couple shares. But if they could get everyone back in the tent, they'd get a 6. But rock fans don't want to listen to other people's music. Country is different. Country is about the big tent. It's got artists who range in age from 20 to 60, with styles that range from pop to outlaw to traditional to alternative, with cowboy hats or baseball caps, boots or sneakers. That's how country became #1. Big tent, not fringes. That's what you do if you want to win. Competition isn't about showing up. It's about winning.