If the record labels don't care, why should commercial radio? They don't have a dog in the fight. Radio stations are not in the music business. They don't benefit in any way from making rock stars rich. People pay money for Sirius, so they should get something different. If they paid for FM, they might get new rock there too.
Radio Stations benefit by staying RELEVANT. Gone are the days where you can only hear music on the radio and through friends. I can literally hear any song, of any genre, from anywhere, using the internet. I no longer listen to COMMERCIAL FM Radio, and haven't for about 18 years. Why? Because every time I turn on the radio, I hear the same songs on my local rock station that I heard the last time, and the playlist hasn't really changed, aside from 1-2 tracks, in the past few decades. Being a hard rock fan, I know there are HUNDREDS of good rock tracks that have come out since then that they could be playing, but they don't. They stuck with the 25-54 demo for so long that they have now become the 40+ demo. The difference? Now I KNOW they could be doing better, but they choose not to. I am listening to tracks anywhere between 5 months before they make it to FM, and over 80% of the "product" isn't making it to the air. They are capitalizing on their audience as they slowly age out of the advertising demo's, and advertisers are slowly turning to other forms of media, where they have an opportunity for better ROI (Facebook, Twitter, Cable TV, Youtube, etc).
Sure, the cushy days of getting promo money from record labels are gone. So, slowly radio has to serve the public with a clear mission (KLOVE does just this) or be subject to atrophy, and eventual death, as the audience moves on. PLJ, like many others, had PLENTY of time to do just that, and chose not to. Even if you accept that the format "died" 11 years ago (recession, PPM), you still had 11 years to reinvent yourself and stop the bleeding. Cumulus was a VERY poor steward of these missions. They are trying to turn that around, but they are so far in the hole (especially compared to iHeart, etc) that they have now run out of runway to make that happen. I have seen them make very poor decisions all over the country, getting rid of popular talent, flipping formats that are pulling in a 3+ share for formats that barely cracked a 1 share (Love 105 in Minneapolis is a great example of that, a 3 share is the best those signals could ever HOPE to get!).
In come the K-Love's, with millions in the bank and virtually no debt. And what's really sad is, from what I have heard, the stations get more investment under K-Love than they got over the past 10 years as a commercial station in nearly every case, despite not having a studio (new transmitters, processors, etc).
Radio pivoted to a more "neutered" sound at the exact wrong time to do so, and it may never recover. And what makes it painful to watch is to see that they were still billing millions of dollars a year, but somehow deemed the 50k/year afternoon guy with an audience as "too much money".