I think the biggest reason it may not be as good of job as Arizona is because you are competing with UCLA for attention and recognition in the media. In Arizona you're the only game in town and your not sharing media attention with another well known basketball school.
I guess the appeal of one job over another is truly in the eye of the beholder. I see the benefit to USC is you don't have tons of pressure because you are not the only game in town, still make a huge salary, tons of talent in your backyard, and you live in a major metropolitan area that has everything possible.