i went to usc for undergrad, and actually one of the things i was most impressed with was the neighborhood. i did not even consider ucla for undergrad AT ALL for this very reason. usc is incredibly committed to their neighborhood. they had the option awhile back to move their campus to malibu, and they chose not to because they had committed to the neighborhood and did not want to just up and leave. they run a number of schools and enrichment programs in the area, and students are known for volunteering and giving back to the community in any number of ways.
it's a working class neighborhood, so i suppose if you're scared of "immigrants" (ahhhhh! people from another land!!) and "homeless people" (what!!! they're real???) then yes, you wouldn't like the neighborhood, haha. however, seriously, grow up! there's a pretty even mixture of USC students and families, and what do you really gain from living in a bubble? i guess you gain the kind of attitude that GermX has... what an achievement! but DPS (Department of Public Safety) is really good at what they do, even if they do look funny on their little scooters. they have jurisdiction in the area, so basically function as a much more present, caring and competent LAPD.
besides, the campus is BEAUTIFUL. absolutely BEAUTIFUL.
on a somewhat related note, for anybody interested, a trader joe's will be opening just a block off campus in the next year!

there still is a ralphs, and a grocery store called superior. and a number of new shops and food places have been opening up in the past few years as well. the nightlife has traditionally not been great around USC, but in the past couple years downtown has been getting awesome, and it's one short bus ride away. and around campus, the 9-0 sucks, but there is the lab and la barca. otherwise, get a bunch of people together and take a cab somewhere, it won't be too bad if you all cram in. monster massive and electric daisy carnival all happen in walking distance from USC, if you're into massive dance parties. if you're into museums, USC is RIGHT by exposition park, so you're walking distance to a lot of museums.