The key difference is that a majority of the miners have to accept the developer's changes and run the new client. The average US citizen cannot refuse interest rate hikes. So it's a transfer of power away from the few and corrupt (Fed + banks) to the few who are limited in their ability to be corrupt (developers + mining pools).
If the developers implement a terrible policy, the miners will refuse to update their clients to avoid devaluing the currency they are working hard to generate. So the power distribution and incentive structure are different. Whether thats a good or bad thing remains to be seen.
[0] http://www.weis2013.econinfosec.org/papers/KrollDaveyFeltenW...