Agreed. Though I'd point out this it's an incredibly long time to leave the infrastructure in place when there is active planning of further violence taking place on the platform.
I went to school here. The PRT was a staple of transit and culture. Being a 70's proof of concept, maintenance and retrofitting were a way of life. The cars were also controlled by DTMF tones that would play over the vehicle loudspeaker.
I also recall one professor telling me that after they could no longer repair the mechanical parts of the PDPs that ran the system, they programmed an emulator that ran on a pentium III but the software itself never changed. The hardest part of the emulation was apparently getting the timing correct as the original system simply ran at the max speed for the original hardware.
Every few years that PRT would have a problem and in addition to getting outside consultation, they'd have a context in the engineering school to fix the problem. Generally the student body was pretty fond of it.