Its hard to have a civil discussion if everyone pulls into a direction you deem wrong and your words are never convincing anyone.
I have similar resentments when people in my company push for docker on embedded systems, because they are used to docker on the server, and whenever I ask them which problem they are solving on the embedded system with docker, they describe things that are wrong.
I don't share the authors strength of opinion on flatpak, although I see the same issues, and I don't want to advertise or excuse strong "tone" - but I understand the frustration.