Supporting a technology being developed only if it's open source. Open source improves equality of access. Open source improves equality of access to being a producer. Open source improves verifiability. Open source removes opportunities for vendor lock-in.
The biggest reason why is that I am generally skeptical that, especially in the modern world, trustworthy gatekeepers truly exist.
The value of openness is (i) ensuring that it's more democratized (eg. usable by many countries instead of just one), and (ii) increasing the accessibility of information, so people can more effectively form their own judgements of whether or not what is being done is effective and safe.
Most fundamentally, I see open source as the strongest possible Schelling point for how technology can be done with less risk of concentrating wealth and power and asymmetric information.
The third option – focusing less on rate of progress, and more on style of progress, and using a norm of expecting open source as an easily legible lever to push things in a better direction – is an underrated approach.
When this libertarian hears about this proposal for an efficient and robust, but unfree, society, they are making a realization that, actually, efficiency and robustness are analogous to material in chess: an important part of winning the game, but not the only part.
Cryptocurrency enthusiasts will often say that they want to improve global finance accessibility, create trustworthy property rights, and solve all kinds of social problems with blockchains. But if you show them a way to solve the same problem without any blockchain at all, they always seem a little too enthusiastic to come up with reasons why your plan would break, perhaps because it's “too centralized” or it “doesn't have enough incentives”.
I would argue that this is basically the failure mode that we need to watch out for: elevating something to being an end-in-itself when it isn't, in a way that ends up greatly harming the underlying goals.
Principles as a tool for coordination.
Principles, not ideology. The subtle difference between these two terms is that principles tend to be limiting, whereas ideology tends to be totalizing. That is, principles give you some set of things to do or not do, but then stop there, whereas there is no limit to how far you can follow an ideology.