I used the term 'permission-minimized.' How many times has someone been prevented from spending their coins? None that I am aware of. It's just another theoretical attack that doesn't work in practice.
Either it is or it isn't. This is the exact issue I'm trying to draw attention to. It is a big assumption to make that the pressure for miners to conform to government edicts will not increase in step with bitcoin's influence on world finance. By the time that happens, and without an alteration in the barriers to entry for mining or the miners ability to control transactions, then mining centralisation will become even more entrenched.
How are you going to feel if a future mining majority decides that Austrianism is no longer fashionable any more, and Keynesianism is back?
500 BTC superwhales could end up with something closer to 500 dollars.It is highly unlikely to happen as radically as you describe. If this were to happen, then most likely we would end up with an Austrian fork and a Keynesian fork dueling it out, which I could see possibly happening. Users would have to make a choice between one or the other, or a combination of the two. This is the likely outcome in your scenario because bitcoin is global and can be forked easily. The dollar or Euro cannot be forked with a new set of rules applied, so this scenario is impossible with legacy currencies.
And given that most likely of outcomes in my apparently extreme scenario, bitcoin ceases to be. You state this in a way that implies an unavoidable consequence: that no-one would risk such an outcome, as the stakes are too high for something as trivial as having a "sound" (i.e. Keynesian) money system, right? I don't believe you're imagining this from the perspective of a) the tiny minority of influential figures in government and corporations, or b) the majority of people who are ignorant not just to cryptocurrency, but even their regular currency.