These rules are hardly arbitrary. They exist for a reason – and aviation safety relies on crew members following them to the best of their ability. That's why pilots have to go through checklists instead of relying on their memory, no matter how many times they've performed a procedure.

Flying a plane with 100+ people isn't the same as doing 10 over the speed limit in your own car. There's a lot more at stake here. While it's inconvenient for crew to follow the rules so strictly, the alternative of leniency is much, much worse.