* Would the software developers suck it up and follow the miners?
* Would the pool of software developers shrink because various developers do not find implementing the will of the miners to be an enjoyable hobby and/or job anymore?
* Would the miners hire new software developers to replace the ones that leave?
* Would there be a fork?
I don't know, but pretending that "the protocol is decentralised, the technology is completely agnostic to anything but the will of the majority" is ignoring the realpolitik of this kind of situation.
Saying that Ethereum implements the will of the majority is like saying American democracy implements the will of the majority. Sort of? But meanwhile there are a lot of empirical studies [0] demonstrating that the will of the people has little to no influence over American public policy. A democratic financial system is much more corruptible than a democratic political system.
[0] https://scholar.princeton.edu/sites/default/files/mgilens/fi...
By only saying that the problems will sort themselves out because a census controls the network doesn't address the other factors that can be influencing the decisions of the majority. Essentially a census-controlled network isn't infallible (i.e. bitcoin block size debate).
No one can come out and say, "We must change bitcoin. You should follow me because I created it."
By removing the founder role, Bitcoin is just that much more decentralized.
If the miners freely agree to accept a fork, were they really free in their decision or did they do it because of peer-pressure or because humans like to preserve groups more than anything else?
On the other hand: What would need to happen to "prove" independency of the organization?
Yes, just like a constitution. System architecture (political or otherwise) can not save mankind from the failings (of a subset) of itself.