I've got 3 degrees from Ivies. I've worked at another's med school for another. I've gotta be honest with you that I don't feel like an open sense of entitlement is accepted or all that common. I work closely with clinical professors who do interviews, and I think they would reject an applicant who communicated such sentiments, honestly. And with extremely rare exceptions, there is no overarching safety net to rescue those applicants from their own words/attitude in a bad interview.
Anyhow, moving on with the "school specific discussion"...with your #'s, there is no statistical reason why you shouldn't have received a secondary from USC. If you have double-checked that everything was received and is in order, can you account for what wasn't ideal for USC that you wrote in your 2ndary and perhaps address it in an update? USC is incredibly concerned with specific issues and is very proud of specific aspects of its education. When they asked why you wanted to go to Keck, did you just say basically "I want to stay in LA. I want a good education." Or did you find things specific to them. Technically they don't accept updates prior to receiving an interview, but the worst they can do is disregard your letter. Update them that you have received interview/acceptances X, Y, Z, but you believe that USC is much more aligned with your educational aspirations b/c of __________, and you would truly appreciate being offered an interview b/c in spite of your fortune of being offered these great choices, you believe that USC would place above these other institutions due to those offerings, etc. Admit that you re-read your 2ndary and don't think your intentions came across as clearly as you hoped.
There is a lot more to the real world than learning that things are earned by connections and the like...and if you feel the world is governed by connections, beware the potential connections you may burn when you offend people who may later be in a position to help you.
Good luck.