One thing that hasn't been noted here is the danger in getting used to seeing stuff U/S on a school's fleet of planes.
I remember renting the C152 Aerobat from my flight-school a few years ago & during preflight noticing that the G meter hand that stays at the max # of Gs pulled was a bit over the max rated & dismissed it with a "huh, must be broken" (which wouldn't have been unusual for that school).
After coming back from my flight my instructor asked me about it as he was concerned as to why I hadn't said anything about it. Turns out that someone had apparently scared themselves a bit a week or so before in it. The aircraft had been inspected & was safe but he was a bit concerned as to why I had flown it w/o checking.
I think that had that school's fleet been in better shape I would probably have said something.