In my experience SoCal has some of the worst drivers in the country. I grew up in Minnesota, where the roads are slippery with rain or snow at least 33% of the time, if not more. Even in good weather, drivers tend to be much more cautious, and frankly, more courteous. Sure, there are some jerks everywhere, but only in Southern california have I had the experience of turing on my blinker and having the car in the lane I want to go into speed up, so that I won’t be in front of htem and slow them down by 2 seconds.
I also call the classic move where someone drifts slowly from one lane to another without signaling the “SoCal Lane Change”.
I think part of the problem is a lot of the freeways don’t have good shoulder that cops could safely pull people over onto. But a lot of it is just culture.