WTF?!?

For one, if someone takes ownership or control of the commons, they are not the commons any more.

For two, it is very much the case that the 'tragedy' occurs absent a mechanism to prevent it.  'forcible ban' or otherwise.  You seem utterly backward on the whole 'tragedy of the commons' principle.  To me.

For three, a lot of us, and especially myself, are pretty leery about individuals 'taking ownership or control' over the certain aspects of Bitcoin's function.  Indeed, the difficulty of doing this is a major 'selling point' of the Bitcoin solution.  In part because of the ill effects of such control in other solutions.