UCLA has the benefits of being a good school in a great location. That's it. When it comes to football they have a TON of headwinds. The school and more specifically the UC system does not prioritize football and while they have pretty good resources/facilities when compared to the top 15-20 programs they are lacking. Also the Rose Bowl is a fantastic place to play a game on New Years Day in front of 100k fans. It is not a great place to play a game on a Saturday afternoon in October in front of 60k fans. It's almost 30 miles from UCLAs campus and most students have to take a bus to get there. It's in the middle of a golf course in an upscale neighborhood with no good way to get in and out.
The USC job is WAY better. Donors care a lot more about football, much better facilities, on campus (more or less) stadium, etc.