Bingo.
As early as the 1960s, the line on L.A. was "70 suburbs in search of a city."
In 1960, 78 percent of Los Angeles County was white---a large number of them were midwesterners who worked in the Aerospace industry.
Today, non-Hispanic whites make up 27.8 percent of the county's population. 224 languages are spoken.
Even if you break those people up into groups by heritage, the concerns and lifestyles of any one of those people living in Sylmar is likely to be different from another living in Santa Monica, which will bear little resemblance to (pick a place).