How do you justify that despite the blockchain being decentralized - that at any time, a dozen different people could immediately or long term ruin or muck with bitcoin’s policies and directions?

I’ll also at this time point out it’s a commodity in effect, not a currency really, but different topic.

Your argument seems to be the idealized “it’s open and no one owns it man” and not the reality that the only part that’s “free” is the mathy database part.