The question keeps getting asked because people say they have problems. Answers (if any come) tells everyone what the problem is for this one user that raised it.
In aggregate we can all see that the problems are not very real for the vast majority of users.
The biggest problem users actually face with using Firefox is that web devs don’t want to support more than one browser and they have picked Chrome now. Or IT departments have blessed one and only one browser on corporate machines and it is the one most corpoware developers build extensions for.
Chasing web standards is a second order problem and will not make the user experience better in a relevant manner for end users. If web developers want an open web, they have to work to support open browsers.
Yeah the criticism is not invalid, but it is also often half-relevant soapboxing and I would wager that is why it tends to get downvoted.