I think you may have a little confirmation bias going there. Lucy and Ricky moved to the West Coast in 1954. Star-driven shows that transferred from radio to TV, like Burns & Allen or Jack Benny, kept Hollywood as their milieu. The 1960s and 1970s had lots of shows—Dragnet, Perry Mason, My Three Sons, Beverly Hillbillies, The Brady Bunch, Three's Company, Adam-12, Rockford Files, CHiPs, Lou Grant—with a Southern California setting, whether or not it was ever said explicitly.

Here's a fun, though obviously incomplete, map of show settings. And, of course, Wikipedia allows contributors to try making a complete list.