Remember that KIIS always paid attention, on the air and in research, to Hispanics. It was more than Rick Dees calling himself "Ricardo Díaz" and was based on the knowledge that a slightly rhythmic lean worked a lot better in LA than a rock or alternative lean world and that too much rock-based CHR would blow away the Hispanics.In the case of KIIS being light on the Blink-182 and Panic! tracks in 2007, that might have been because those songs were being covered well enough by KROQ, Star, and maybe even Jack FM and KBIG (well, maybe NOT KBIG, but I'm not sure) and with stations like Power and The Beat, etc, KIIS was still staying light on the mainstream tracks, dayparting more to times when adults and not kids would be listening more. Now these songs work a little better when mixed with what's playing today, and still have enough familiarity from KIIS and the other stations that played them that they just work.
As you say, there were enough rock voices in the market, too.