A group can only corrupt bitcoin if they are in control of so much that they would never want to. If Bernanke had personal income of half US GDP do you think he'd be willing to debase?
I'm not worried about debasing, more about huge transaction fees being inflicted.
Oh, that's no worry, if the transaction fees are huge it will just incentivize medium size players to move in and offer slightly lower rates. Being the biggest 'bank' because people are choosing to pay you for your services is way different than being the biggest bank by forcing everyone else out with laws and weapons.