Obviously IWM don't just want profit - they want more profit. Other organisations on the airfield will be feeling that same pressure too.
Having been in a business driven to closure by relentless hangar rent rises. The needs of an airfield owner are often outside most operations contexts and when TFC move out there won't be any real profit in whoever moves in - especially if they cancel a huge revenue event. Is the IWM being driven by a new CFO/accountant with no IWM or Duxford experience? Perhaps one who sees more profit in car parks than airfields?