Socal- why are you asking for opinions on the matter when you are clearly already decided on Northridge?
It is fine to be set on Northridge if that is the school you want to go to. Your right, the CSU's in general are said to have the "learn by doing" feel. For me, the UC's are far more substancial then the Csu campuses and I tend to think your statements about Harvard and Cal students not getting into big firms seems a bit biased and incorrect. I am thinking I would accept the Harvard biz grad with the same stats as the Northridge grad, stuckup or not.
The students going to the two UCs you are passing up will be a couple steps above those at Northridge. Santa Cruz has an average HS gpa of 3.7, where as Northridge has an average high school gpa of 3.1. That is quite a difference. You will find the more study minded students at the UC and I also tend to think you will not get the college experience at Northridge, as it is a commuter school.
All and all, it seems like you are set on Northridge, but I'd like to just ask you to visit Santa Cruz and Riverside, if you have not already. I am thinking you will be pleasantly surprised, because you will finally see the campuses from your eyes, and not your family's impression.