I also have a great dislike for pollution and crime, I factor it into my city ratings higher than other people do. Clean air and water are high up on my priorities. Take SLC for example, absolutely gorgeous city, unbelieveable recreation, excellent public transit, sweet night life. Without the pollution I'd give it a 9. Factor the pollution and west valley crime in, it's a 7 at best.
LA without the pollution and crime would be an amazing city. You can even keep the artsy douches and it would still be grea.t
I spent 26 years in Florida and have never been as happy as I have moving to LA. For me, the city offers:
Beautiful weather
Lots of neighborhoods with vastly different vibes (Hollywood Hills, Silver Lake, Santa Monica, DTLA, etc.)
Beach
Hiking in the hills
Lots of creative types (art, writing, music, film, theater)
Great public transit options (Uber, Lyft, Rental Bicycles, Bus, Subway)
Lots of points of interest that are hidden away... no shortage of interesting things to discover
Lane splitting on a motorcycle is legal
Higher standard of income (jobs tend to pay more, etc.)
Economic opportunities that aren't available anywhere else (the chance to work or attend private events, parties, etc. held by celebrities, studios, executives, etc.)
For me the biggest cons are parking, traffic, and homelessness. Being on a motorcycle negates parking (easy to find) and traffic (I can cut between the cars). The homeless problem is just a matter of moving to the right neighborhood where it's less of an issue.