They banished him because he was disrupting their sandbox. He saw the urgency of getting rid of those who are doing ...
.... just two things. OCCUPING a SEAT and using it to enrich themselves. Those who will not leave when their time comes because it's the best-paying, cushy job a person can have. HE RIGHTFULLY wanted to find new, younger challengers to occupy those seats.
So, depending on your point of view, he was pushed out, he got tired of 
Or he quit to continue his work from the outside of their sandbox, so he at least doesn't start his day by having to .
He is still finding and supporting challengers to the do-nothings. We still help with his activity by sending him a check every month.
A check with no names, addresses, or other IDing info. Just the necessary stuff to make it work. IS he the answer? Who knows, but he's doing something by kicking sand in the faces of those doing nothing.
At 78, you know when it is time to hire younger help.