Hmm, well people will not be spending their bitcoins recklessly. If they do spend it so for e.g. on a house or in another company, they still hold the power, with the underlying value of that power being bitcoin. The only real spending that would occur would be on depreciating assets, which would only account for a small amount of the purchases made. The rest would be hoarded in appreciating assets, so they never lose control of the power they first received with the massive wealth disparity that may come from bitcoin.