It is the simpliest explanation. In fact it was stupid and arrogant leadership mostly.
There was no disagreement, as we didn't say a beep then. They made those stupid decisions all by themselves, and didn't listen to any advice. The better people just silently left, shaking their heads.
It's the laziest explanation.
Did you ever ask yourself why, for example, all of the calling convention code paths were consolidated into a single code path? It wasn't to make a single, inefficient code path as you claim.
It was to provide a gradual transition for clients to a better designed calling convention system which could then be optimized for actual client uses.
The goal was never to create the fastest possible VM at every single point in time. That's where I think you never understood the goal of the project, and that's where I think you've never understood the goal of p5p.
The goal was to make something that works, continues to work, and can be improved while continuing to work. That's why you're no longer welcome in p5p -- because your goals and your actions are incompatible with that.
I wish you understood this. You're very smart and very talented and you have a lot to offer, if you can get out of your own way and accept that people who don't share your exact goals in the exact same way aren't irredeemably stupid.
How odd then that ~90% of the discussions about ditching Parrot were primarily complaining about the deprecation policy and first-class Rakudo support, not speed.
I suppose you would know better though, being objectively smarter than everyone else who ever made a decision about the project. How unfortunate that we can't take your word for it; we can only read all of the public discussion about it.