People who have dedicated their lives to a job like Beyer has for so long, don't know what to do with themselves if they leave it. Plus, as you get older it's harder to change. So combine the two and you have a situation where I don't think he will be able to retire. It's not in his vocabulary. What would he do with himself if he quit and had all that time on his hands?
Or, he could surprise us all and pass the mantle to a younger Judge deserving of the position. That would be nice.
He could take a visiting professorship at literally any legal faculty in the world.