Well simply put, in the pre-netlet days (Fox, WB, UPN, CW, etc.), KTLA was one of four independent stations in Los Angeles (as opposed to New York City and Chicago, with three each), and there was so much children product (syndicated or otherwise) to go around. I could speak in regards to the 80s and 90s (as I've spent a bulk of my childhood here), but the bulk of the syndicated cartoon product was spread between KTTV and KCOP (the latter station had Ninja Turtles and He-Man); KCAL (previously KHJ) didn't air much kids programming until Disney bought the station in 1989 and pretty much discontinued kids programming by the time the old Viacom (now CBS Corp.) bought the station in 2002, although it gradually started moving away from the kiddies in its last years under the ownership of Young Broadcasting.
KTLA was a station during the Gene Autry/Golden West era (and into the early years under Tribune ownership) that catered to a more mature audience, although they did air its share of family-friendly programs, like the Three Stooges, The Munsters, Leave it to Beaver, Happy Days, Laverne & Shirley, and its long-running Family Film Festival movie showcase on weekend afternoons (very similar to WGN's old Family Classics on Sunday afternoons).