Arbitrary means that the choices were random choice or personal whim as opposed to any reason or system.
Just having different systems, or choices, does not mean it is arbitrary.
If your list includes, good food scene, but mine doesn't, that doesn't mean that I could call that arbitrary. Good Food is obviously a part of quality of life.
NOw, if you included, "lots of brightly colored flowers", then we are talking pretty arbitrary.
YOur refusal to explain why you consider the list "Arbitrary" I guess is sort of your way of admitting that your issue with it, is that you don't want to admit that California, has a shitty quality of life?
You try so hard, and yet still fail so badly, I almost feel sorry for you.
These list are based upon the personal whims of whomever is making them. They pick the things they find important, which may not be the same thing the guy at the other magazine finds important. To you good food is obviously a part of quality of life, but to the germaphobe that never eats out, it has no impact on them at all. Quality of life, just like happiness is a purely personal thing that changes from person to person. What makes you happy may not make the next person happy..
Another reason they are arbitrary is that much depends on where you live in the state. In the example of the OP heavy traffic and the pollution of LA brought the state down. So, if you are one of the 90% of the residents of Cali that does not live in LA, that has no impact in your quality of life at all. If I live in Idyllwild and never go to LA, then how can what happens in LA bring down my quality of life? By the same token to use your example of a good food scene, if the quality of life score goes up because of the food scene in LA, how does that impact the person in Idyllwild?