I think the question on who controls it is a bit more complicated than to say that the user controls it. Users have little control over the development of Bitcoin for example. It's more accurate to say that developers and miners control bitcoin. It can be argued that Vitalik Buterin controls Ethereum, he is certainly extremely influential in the direction on Ethereum development. More recent cryptos like Decred are leading the way in refining more decentralised and sustainable governance models but there is still a lot of work to be done in this space to achieve truly decentralised and efficient governance.