What's the meaning of Philanthropy's biggest contributor?
IIRC the Wiseman's Committee itself is a fake front for their successors, the Patriots. By the time of Solid Snake, the Patriots have so many gambits running in parallel that one is that they can use Philanthropy as a way to get Snake do things they want. Need a scapegoat? Leak a new Metal Gear for Snake to show up and take the blame. Need to control Ocelot's plots? Send in Snake to take him out.