Look, the reason why there's a fuss about the instamine.....They cannot afford to have centralized screw-ups like what happened with Dash's instamine
This is not a game with rules. As you are pains to point out, it's a decentralised free market in which developers are free to tweak whatever parameters they like subject to 2 conditions:
[1] - their revisions are accepted by a majority of miners
[2] - their actions expose them to the risk of market revaluation
I was hoping you'd type that. This is why Dash's instamine is so controversial. Because we know a few things:
1) Dash's developers were able to mine a portion of the coins unhindered as the linux wallet they posted on BCT wasn't working
2) We do not know who controlled 51% of the hashrate at the time. But, since we know that the coin was available on linux-only, and that the developers themselves obviously were able to mine during the entire time the instamine occured, we can assume that the developers controlled a significant portion of the hashrate.
Thus, the conclusion can be that it wouldn't have mattered what anyone said, as Evan Duffield changing the block reward by himself wouldn't have required any input from anyone else if he owned 51% or more of the hashrate, which is very likely that he did along with Internetape. This is what I'm talking about by saying Dash had many centralized decisions done. Even the namechange from Darkcoin to Dash was a centralized decision done solely by Evan Duffield, to which his co-dev Vertoe quit the core team because of it.
Such centralized actions simply can't or rather, shouldn't happen in
Decentralized currencies. Having those things happened means the coin is not decentralized anymore, Dash simply is centralized.