Despite beliefs otherwise, California isn't any more "hostile" to our sport than any other state and it isn't political or "culture." I can't think of a state (or country) that hasn't had the same issues. On the rare occasion, there are some communities that are generally supportive of racing, but they are exceptions.
The loss of the dragstrip and road course at Auto Club is also unexpected considering NASCAR owns the track and isn't much in the drag racing or road racing business. Vintage races will still go on at Willow Springs and Buttonwillow, the only change being making the same extra miles drive that was done between 1989 and 1995, between Riverside's closure and Buttonwillow's opening.
As far as Long Beach, and many other street races, many are there for the party and probably couldn't tell you much about the race, much like crowds at The Kentucky Derby or even at the Indy 500 in the infamous "Snake Pit." They probably couldn't tell you who was leading if their life depended on it. Again, not just a California thing. Boxing and horse racing used to be huge sports, but interest has declined dramatically in them as well.
Southern California still has a few ovals, drag strips and road courses. Again, that's down to development and dwindling interest than any other perceived issues. And, again, this isn't unique to California, or Southern California, it's happening across the U.S. There aren't any fewer tracks close to Los Angeles as there are to New York. For example, NASCAR has removed large swaths of seating from their tracks all around the country and many short tracks have closed.