Back in the day when 'sensible engineering" was common we had a separation of the stem/headset clamping duties. One fixture secured the stem into the steerer and another would trap the headset bearing adjustment. This was the threaded steerer/headset and the quill stem. With this system one could let the stem be only as tight as needed to allow for steering forces (which are very minor if the headset works halfway well). Then when one fell of bumped the bars hard and they got off center it was straight forward (Yes, intentional pun) to re align the bard with only your hands and legs (ft wheel between the legs).

Today with both functions combined the stem/steerer clamp needs to be tight enough to resist the bump and bearing getting loose forces which are greater then the steering ones. So when the stem gets shifted on the steerer it takes a wrench to loosen before straightening, or the possibility of damage exists.

As we march forward we go backwards too. Andy.