that's... not a valid argument for this discussion? market share and user conservatism has no connection to concerns about basic safety affecting everyone
judgement should be applied equally, every user and every product
I believe the intention was to argue against the notion that 95% of users don't read release notes. The contention seems to be that, because Firefox users are more technical (or enthusiast, perhaps), more than 5% of Firefox users would read be aware of this change.
Now I agree that this change is not being communicated properly but to claim that the Firefox user is similar to the average computer user is not something I would agree with.
Is Mozilla content with that market share? If not, it must act with the assumption that its users are average.
I agree with you that Mozilla has certainly dropped the ball regarding this change. Much like pocket, the Mr Robot ARG, the Quantum update, DoH with Cloudflare as the default provider, and so on. But again all but the Quantum update have been user configurable, and in my experience, have not been reverted unlike my browser preferences on Windows, where Edge hijacks anything and everything with very little recourse.