In that thread there's stuff like 'Add-ons before WebExtensions could access the AMO fine and the sky did not fall in' and similar sentiments expressed in the issue post itself. It also seems like a thoroughly unwinnable argument, you're basically saying Mozilla's security policies are pointless because things were just fine as they were. They obviously disagree profoundly and aren't going to be convinced by this.
"I am happy to be corrected on this. If you have any specific explanations you would like me to provide to our users, I would be happy to pass them on."
We also supported Mozilla's choice to move away from the XUL API.
I and most of the other core contributors are in favour of of capabilities-based security with explicit permission granting, not just in Firefox, but in general.
We believe that it should also be possible for users to have their software do what they want it to do. Part of that is letting people make their own decisions about what level of risk they are willing to accept.
We are reasonable people. We have been told in non-specific terms that something is unsafe that we think is useful and reasonably safe. So we have asked Mozilla (several times) to explain how it is unsafe so that we can update our beliefs if necessary.
We are asking because we know from experience that Mozilla employees generally have a lower tolerance for risk than us (the developers of tridactyl) or many of our users. Fundamentally, that is OK, but here Mozilla is asking us to do a bunch of work and change our code in ways we don't really want to do so that it more closely matches their risk tolerance than ours.
They can choose to manage their ecosystem how they like, but we in the ecosystem rightly also get a small say.
So we are asking them to say why and trying to negotiate a compromise that will be acceptable to all of us.
It's a quote from your own devs in your own thread, and there are other similar ones. I don't know what your exact argument is but what's there sounds adversarial and reads more or less like telling Mozilla, Morrie Kessler-style, that they're being an unconscionable ballbreaker. There's probably some better, clearer way to present whatever it is you have in mind. Morrie didn't win the argument either.
We don't complain about walled gardens.