Penn has cash - the endowment is like 20 billion. Temple doesn't, it's a state university. Penn will keep University City gleaming even if the city falls apart because they are the landlord for most of the area which allows them to be a pseudo-municipality by creating their own rules for land use. They own the property for several blocks around the university and lease it to developers that will meet their standards. This is on top of their security apparatus which is also well funded and about the same size as Temple. But you can't just police your way out of the problem - the thing that makes UCity safer is that its development and management allows Penn to operate much more like a campus than a city university.

Yup the 80s-90s was about the worst of it. Starting with the Sansom Common development in the 90s replacing the "dead zone" parking lots north of campus and then further development on the west side of campus in the early 00s things got better.

You're not wrong, but I lived in West Reading for a while as a student at the hospital and the Reading Public Museum and the adjacent park and planetarium are a lovely area to spend a day.