It’s not about making umps look foolish or training them to see better.
Calling balls and strikes looks easy, and maybe in local Beer League Softball games it is. But in MLB, it’s a job that requires determining if a projectile traveling 95-100 mph touched any part of an invisible box with varying dimensions, and doing so live with no help from any electronic tools. Oh and also includes being scrutinized by fans watching TV that think they have a better view and commentators that have access to replays, and now being checked against an electronic sensor system. It’s an insanely difficult job to do in the first place - probably the most difficult task of any official in any sport - and the failure to be perfect opens the door for someone who thinks you look foolish and just need to “see better”.
That said, Bucknor does often look foolish and needs to see better…