All right, everyone brace yourselves, because I am about to disagree with David.
I was about to go to work for J.J. Jackson at KEDG in 1989 when GM Bill Ward announced the flip to K-Lite. (And he even had the indecency to announce that on my 33rd birthday.) And I always disagreed with his decision -- and would have, even if I hadn't been "waiting in the wings" when Ward made it -- because the station was just beginning to catch on.
April, 1989 was the first month that KEDG's commercial inventory was completely sold out, a fact mentioned by J.J. during the final broadcast (my copy of which is available for listening at ReelRadio). It had an audience that listened for long periods of time ... if Arbitron's PPMs had been around then, they would have thought they were malfunctioning because of the lack of "20-minute" listeners. The Edge was an intelligent redo of the old free-form progressive rock format; J.J. found on-air talent that knew the music and could put together music sets without a pre-programmed playlist. Small wonder, then, that I jumped at the chance to come on board (I was going to coordinate production and remotes and be the utility jock).
KEDG was proving one point that David alludes to in a sideways fashion: KEDG never "blamed the signal". Everyone knew that 101.9 had reach, even then. It reached all the way to Ventura back then, before 101.7 in Carpinteria went to a B1 signal, and had been successful in the 1970s as "The Album World of KUTE-102" and as "The Quiet Storm" in the early 1980s before going AOR as KMPC-FM. Bill Ward simply fell into the same trap that KKDJ's general manager did 15 years earlier ... letting their personal tastes dictate what kind of station they wanted to manage. (KKDJ's billings were at a high point when they became KIIS-FM as well.)
Ward, to his credit, recognized his mistake after a few years, but made a bigger one in the process. Instead of going back to what worked, he tried to do the "mellower" version of AOR ... AAA. And there I have to agree with David. "Channel 101.9" was doomed from the start, because too much time had passed since the original AAA, KNX-FM had passed from the scene (it is also my opinion that once CBS changed 93.1 to KKHR, they would never be able to regain their old status, which is a big part of why the attempt to bring KNX-FM back from the dead failed, the other being a failure to properly recreate the old atmosphere).
Here is where my friend David errs. The AAA format on KSCA was not the same as the AOR format on KEDG, and therefore using the subsequent success of Regional Mexican on that frequency as an argument against KSCA (although true) is a confused argument against what SRF had said. (Maybe you shouldn't have used the phrase "rock/AAA" to describe KMPC-FM, as that seems to have been the point of confusion.)