This reminds me of my time at Virginia Tech (recent grad here). Those of us on upper quad never locked our doors. This had apparently been a thing on upper quad all the way back to the start of the university and that only changed when we moved to the new buildings with electronic locks. I'd say once we moved into the new dorms 75% or more of us were jamming the doors/locks so that they wouldn't lock. This only really started to change after "the adults" started reprimanding people for refusing to lock their doors (There were concerns about ability to compartmentalise/hide in an active shooter situation as well as potential fire safety issues).

It was a really unique and pleasant experience. So much less stressful being able to completely trust the people around you. It's a shame that the tradition has started to die out.