I dunno! Those who have operated machines for gain, having the ability to make quick changes can spell a huge difference.
Some of us old guys who worked in production shops can attest to the need for easy-to-change drill chucks. I spent weeks drilling holes on drop spindle mills (BP types, with a quill). This was before the missile was in full production (in the R&D phase, before hard tooling was available).
Because the work involved was for defense purposes, all aspects of the features were subjected to inspection, thus there was three changes of cutting tools per hole. One had to go to the desired location, spot drill (we used only center drills for this purpose), open the hole undersized to proper depth, then open the hole to the desired diameter by double drilling. The double drilling operation assured that the hole was not oversized. All holes requiring tapping were tapped after the parts were finished (either alodined or anodized), never before. Holes were tapped using tapping heads.
Imagine doing those operations without self tightening chucks. Very cumbersome and slow. Still, keyed chucks were common.
The shop was equipped with two Wahlstrom quick change chucks. They are, like the others, self tightening. The big difference is they can be changed without stopping the spindle.
Are you sure you'd like to see them outlawed?
H