The SDSU incident is highly unusual and sorry if this was a big turnoff for the campus. Both my younger son and niece attended SDSU and had no issues with campus safety when they were there. Not sure what you mean about your that SDSU looked “rundown”? The many times I have visited the campus, it appeared to be well kept and clean.
I would compare the major programs between the 2 schools. Look at the curriculum, the requirements to declare the major, and electives of interest.
Both have good reputations but completely different social scenes/vibes and neither my niece or son would have been happy at UCSC. Too remote for them and preferred the city life.
The housing situation is much better at SDSU vs. UCSC especially with the Honors college and the 2 year on-campus requirement for Freshman/Sophomores. Also plenty of off campus housing choices for Junior/Senior year.
There are several discussion threads you can look over regarding SDSU and UCSC pros and cons:
There is no perfect school but where a student goes for Undergrad will not define them, it is what they accomplish while there that will make them successful.