Perhaps their ratings are also low because they are boring? KROQ used to be unique. Think of the Rick Carroll era with all the drop ins or early Kevin and Bean showing up at Rick Dees' house. Today they sound like any other corporate alternative station. I listened on Saturday late morning a few months ago. I heard songs (mostly old), promos, and long stop sets. I'm sure there was no live jock in the studio. The only difference between KROQ and AMP is the music. The formatics are very similar.
As someone who's streamed KROQ periodically since that became available, I think part of the problem is that KROQ used to be a station that had a sense of unpredictability about it, you never knew what they were going to play and if at that moment you're listening they'd surprise you with a new artist or a new song by an artist you already know. KROQ I don't think has broken an artist since Foster The People and Imagine Dragons (and I'd rate the latter as a "maybe"), and that was at the start of this decade. Kansas City's 96.3 The Buzz currently acts more like vintage KROQ than KROQ currently does, as the amount of currents KROQ plays number in the teens (maybe even the low teens), and that's made the station feel more automated and bland. At this point, KROQ is leaning so heavily on its historic library that it is one step away from becoming a so-called "Classic Alternative" station, which couldn't be further from the station's mission and would make Rick Carroll spin in his grave.
KROQ, despite it all, still has a better playlist than the one-size-fits-all generic iHeart that's been trying to kill it. But XTRA 91X also has a better playlist (and has stuck closer to its original mission of breaking new music) and it's getting killed by 94.9 in San Diego, and KRBZ 96.3 The Buzz in Kansas City is getting bruised badly by a bland Cumulus station. So I don't know if the problem is the lack of new music or something else.
Maybe the problem is the music itself. Indie rock, in various forms, has formed the foundation of alternative stations, but it's always been accompanied by another genre or two. New wave during the 80's, grunge in the 90's, pop-punk and nu-metal at the turn of the millennium (and big beat for a brief period), etc. But none have clashed so flagrantly with indie rock as the current indie pop/alternative pop movement, which often doesn't even superficially sound like rock music. You can't segue from an Offspring recurrent to, say, AJR or SHAED with any grace, and the more rhythmic sound of alt/indie-pop has to be a turnoff for rock listeners. At the same time, fans of the more rhythmic alt/indie-pop sound have to be sick of hearing Soundgarden or The White Stripes inbetween their favorite songs.
Out of all the alternative stations that I keep an eye on, the one that's doing the best is KPNT 105.7 The Point, which has a staggering 6.6 share in St. Louis and is soundly defeating its generic iHeart challenger. Its solution to the current dilemma is including elements of active rock into its playlist, minimizing the alt/indie-pop and concentrating almost entirely on new indie rock with a random active current or two mixed in ("Monsters" by Shinedown, "Lover, Leaver" by Greta Van Fleet, and "Panic Attack" by The Glorious Sons seem to be the choices at this moment). The Point also plays more currents than KROQ and 91X do, but again, considering the aging radio audience I don't know if that's a factor.
Would The Point's solution work for KROQ or 91X? I can't really say. Los Angeles and San Diego are vastly different markets from St. Louis. But I were programming KROQ I'd be digging around for something fresh and new and try it out before the station is totally lost. Maybe the solution is with the dirty rock movement, maybe it's something else. But KROQ can't stay stagnant forever, or the station will just become a memory.
I also don't think the alternative/indie-pop genre will go away anytime soon, so we could be in for a pretty dramatic format break depending on how things go.