CBS radio, for the longest time, even going back to the Infinity Era, or even Infinity pre-CBS, seemed to run their Alternative stations with an Active Rock lean. CBS also tended to run tight-playlists on their stations, maybe not as much as Cox and Clear Channel, but certainly more than Entercom.
In the 90's Infinity launched KOME San Jose, K-Rock in NYC and reimaged 96.5 The Peak in Denver as these in-your-face, Howard Stern in the morning, Alternative stations that bordered on Active Rock. While KROQ Los Angeles somewhat bucked the trend, by still sprinkling In more female-friendly artists such as Jewel, Sixpence None the Richer and Dave Matthews Band, even KROQ eventually moved in that direction.
Then again, even as far back as 1989, the management of KROQ was lamenting about not breaking Guns N Roses 2 years prior. By this time, KROQ seemed to want the shed its euro-friendly, post-punk, synth-pop sound, and move on to more conventional rock music. By the early 90's, KROQ, like most Modern Rock stations at the time, starting playing Grunge music. The only difference was KROQ played this music long before other Modern Rock stations, and in a much greater frequency. Under Kevin Weatherly, the station ran a Top 40 rotation of STP, Nirvana, RitM and so on. In 1992 and 1993, most of the European music was slowly scrapped in favor of this new sound. Artists that didn't even hit the Modern Rock chart, or just scrapped the bottom of the chart, would be in the Top 10 on the KROQ charts in both those years. In LA, this worked at the time, with the station finally having Arbitron success it hasn't seen since the mid-80's. While KROQ wasn't the hard rock station it was in the late-90's and much of the 2000's, KROQ in 1993 had more of a hard rock lean then most Modern Rock stations of its era.
While the approach worked for KROQ, it didn't necessary work elsewere. To me, it seemed like Howard Stern was the only thing that kept the ratings high on most CBS alt-rockers. I will also note that many once-great Alternative stations went down under Infinity/ CBS, including WHFS in D.C. The Alt stations that CBS didn't flip, like Live 105 in San Francisco, would suffer in the ratings through the 2000's. Then again, maybe changing up the sound that was developed when Entercom owned Live 105 in the late 80's, through the Mid-90's, didn't help matters. CBS knew who to run heavy alternatives stations with shock jocks in the morning, and little else. Which is why more Adult-oriented Alternative stations, such as XRT, suffered under CBS.
I will say though the new Pop/ Alternative focus of the Entercom stations somewhat surprises me. Entercom owned the great LIve 105 between 1986 and 1997, which was very adventurous for a commercial Alt Rocker. They played Grunge, Synth-pop, Punk, Hip-Hop, just plain Pop, hell even Tony Bennett. Live 105 was also one of the last major market Alt-Rockers to still play European music, even after most Alt-rockers became predominantly Grunge based. Live 105 throughout much of the 90's would only spin their top record 30 times a week, a far cry from today were that Post Malone song, which sounds like it belongs on a Hot AC station, is played every hour.
KROQ Caught Between Rock and a Hard Place - Los Angeles Times (latimes.com)
Smells Like Top 40? : As Alternative Music Gains Popularity, So Does KROQ Radio - Los Angeles Times (latimes.com)