Call me a mild sceptic, but for whatever reason, a lot of rock bands (The Who, U2, Bon Jovi, The Smashing Pumpkins, Stone Temple Pilots, and R.E.M.) have less listeners on Spotify compared to the likes of Lana Del Rey and Kendrick Lamar, neither of which are exactly hitmakers. So I don't know if rock is in, as a whole.
But back to the topic, KVIL is doing well with an active-friendly playlist because many people in Texas still have a soft spot for late 90s/00s hard rock, as one can see by the successes of KTBZ and KISS-FM, the latter of which is in what was once called the Heavy Metal Capital of the World. It's not very likely that you can replicate this success in some other places in the USA, especially in cities like New York, Miami, or even Boston.