LA - Why do people live there

Just got back from a vacation to Joshua Tree with the family. The desert was wonderful. Still some spring flowers blooming, nice cool days to hike... But we flew in and out of LA which was a mistake. The traffic, the smog, the craziness... The kids loved going to the entertainment museum and walk of stars (we stopped for one night in LA) but for the adults it was a huge chore. Its hard to understand why people put up with that traffic every day! I guess they get used to it, just as I have gotten used to our milder (but still bad) traffic in the bay area. But the smog?? Perhaps it was just a bad day or two when we were going out and coming back in... but LA is looking more and more like Mexico City. You can hardly see anything anymore -- you don't notice the tall buildings in downtown or the mountains until you are right on top of them. Why don't people who live there do something about this?