I’m really not sure. This is a fundamental political science question. A benevolent dictator is always nice, but how long does the benevolence last? In the beginning, a foundation might seem that be aligned with the interests of users in mind, but will that always be the case?
I would agree with you that perhaps coin-holder based governance is not the ideal governance system. There is a research being done in new governance systems as well that can replace coin-holder based. Take a look at Futarchy, a very young and novel idea created by Robin Hanson. There is a great post about it by Vitalik: https://blog.ethereum.org/2014/08/21/introduction-futarchy/
Also, keep in mind also that in the cases of both Foundation-led and coin holder-led, the power still ultimately lies with the people, because they don’t have to go along with the changes suggested by either the Foundation or the on-chain governance system. You can draw a similar analogy to the idea of governments and revolution in the real world. It doesn’t matter what kind of government you have, whether its a monarchy, representative democracy, or dictatorship, in theory, the power lies in the people due to their ability to revolt and disobey/replace the government. Now of course, in the real world, revolution is messy and difficult (due to the imbalance of power and monopoly over force). The hope is that in Blockchain, this sort of “revolt” against the governance structure is easier and less violent.