That said, perhaps it is time to discuss some of the actually viable schemes which have been previously proposed for this. It's quiet easy to construct ones that aren't so obviously broken and which don't have terrible costs like breaking pruning, lite-nodes, etc..
Where is it?
For months we've been told that miners don't matter, individual users don't matter (even vast majorities, apparently), it's only either the "full economy", "Core", or "node operators", but there so far haven't been any steps taken to quantify how to measure anything but mined blocks.
I'm usually not a fan for MP, specifically for taking as extreme positions as he does. But I will applaud him for this, simply because it's proposed a partial solution to this conundrum. Maybe not, as you say, a valid solution, but at least one that was flawed enough for you to say, as you said, "it's time to investigate valid schemes" to do this.
However, that tone you take previous to that concession, seems too derogatory.
It would be interesting to find out how things would fare for a Bitcoin without the people who spot flaws in these cryptographic proposals in seconds flat. Interesting, but I suspect not so good for the market price for my Bitcoins.
This was not MP inserting brand new code into the network. This was a proposed idea. Maybe not a ready for primetime, and I suspect that even without the braintrust that claims they'll leave if they're not at the helm, there would be others that would spot the flaws you claim to have spotted long before such a change makes it to production.
Come to think of it, here's a proposal I know will sink like a lead zepplin (I just enjoy that phrase).
Remember at the first Republican Debate, where Fox asked each of the candidates "will you pledge to not run as an independent should you not be appointed the nominee"?
Wouldn't it be nice if you guys would take a pledge and state that you'd continue doing your best to contribute to Bitcoins code base, even in the event that the community chooses new leadership? They're not rejecting your past efforts or even current work, just one sliver of your final vision for Bitcoin.
And as you and others have said before - you all seem to have a lot of Bitcoins, both directly owned AND time-locked. To just declare Bitcoin a failure over such a simple thing and abandon those time locked coins, just seems short sighted. And you all seem like smart people, I don't get how you can really think that such a minor event ought to be the end of everything as we know it.
After all, I was a fan of a lot of Mike Hearn's work and essays, but was equally unimpressed with his parting actions, and would hope for something more mature from the people who have the most vested interest in the system, and who have contributed the most to it, than just walk away and call it a failure.