It's a library. At a university. It is a place of learning. People are allowed to consume information. We were specifically instructed not to interfere beyond asking people to move to more private areas if the content was disturbing someone around them.
My job was to make sure the printers were working, not to judge people. All kinds of potentially objectionable information much worse than porn is easily justifiable on univeristy networks especially.
We had a similar policy on DMCA strikes. We did reach out to students and ask them to not torrent music on the school network but we never reported them. Student fees paid for the network and our salaries, we worked for them.
I had some friends that ran a CS server out of their dorm room, nobody in IT cared.
Wouldn’t parents set up something similar when they first get a contract for their kids? If I had mine on by default, wouldn’t they insist on having one?