That ship sailed a while ago. Ethereum has already used its market position to de facto interfere with the transactions they declare immutable on the project home page. [1]
Oh, yeah, I forgot. Dollars are much better; a central bank (actually, any bank) can create arbitrarily many of them and flood the other banks and the market with cheap money, causing things like the subprime crisis. Much better than crypto currencies.
Airplanes can fall out of the sky at any moment, but you're still less likely to be hit by one than if you're standing on a rail waiting for a train to dodge around you.
Inflexibility is not an advantage unless you're dealing with formally describable, proven systems. Human behavior and economics are not.
