there is talk of corruption - but surely he would be better placed to deal with it as President?
This is an odd one - but surely if you are in a position of power like this you seek to expose the corruption around you and if the corrupt ones make you quite, then you can walk away with your head held high.
this way he has lost all credibility and looks as if he is having a strop and is then making up a reason for quitting.
The worst think about this, however, is that is clears the way for Giles Clarke to get the role, which would be a disaster...