Perhaps they still think he's OK , perhaps they haven't got anyone else who will step up to it, perhaps no-one wants to rock the boat - I simply don't know
I don't know either, @basiliskstare, but IMO it doesn't say much for the trustees' judgement if they're content to just allow him to go on destroying what Invictus is supposed to be about
Of course they wouldn't welcome the chaos he'd try to kick up if removed, but what's the alternative ... just to go on enabling him until there's nothing left?