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.