I want robo umps, but for those against robo umps, I have a counter proposal. Collect comprehensive and fair statistics on all umpires throughout the season. In the off-season, the worst 5% of the ML umpires, as determined by some calculated metric, either lose their job or get sent down to a lower level of pro ball. Replace them with the best minor league umpires.
That would result in more Quinn Wolcotts and Pat Hobergs, and fewer CB Bucknors and Angel Hernandezes. Stack ranking is common in tech; the game would benefit from umps getting the same treatment.
Maybe, for those who get bumped out of the major leagues, they get one more chance in the minors. If they are in the worst 5% of minor league umps the following year, they get fired. That way, a single bad year doesn't necessarily end an umpire's career.