I decided to see why he left.
His Wikipedia page has pearl of insight in it:
"On the program 16 November 2008, in an item about Oyster fishing in Truro, John revealed that he is allergic to oysters."

Who the shit watched that programme and said "THE WORLD MUST KNOW ABOUT THIS! TO WIKIPEDIA!"
( Malchick, Fri 29 May 2009, 1:36, archived)