If you want to put it very simply: these people on top control the whole economy system and therefore got pretty much unlimited amount of money to do whatever they want. So eventually that leads to bunch of powerful people meeting up and seeking a goal they've been unable to achieve: control the whole world
This current system leads to big corruption and needs to be replaced with something which doesn't even give this possibility. This is essential once the evil have been taken out or we just repeat the same mistakes later on.