There is a swearword used, but it’s not in the context in any way uncivil, as the plural "you" that it is referring to is an abstract person, a hypothetical entity – not any actually involved person. (In this case, the potential future group of people at Mozilla who might decide to override an explicit choice I made for their own convenience)
The topic is a choice that Mozilla plans to make, and is questioning users, and more about.
The decision has not been made.
My argument is that, if Mozilla (and whatever users Mozilla asks to give an opinion), choose to override the current decisions of users who do not want telemetry, and require a new hidden opt-out, then that would be proof that they (as group) don’t really care about the users choices.
The user I was talking to has no power in making that choice, nor do I. Nor is all of Mozilla making that choice.
I was using "you" with the meaning of the German word "man", (I’m natively German): one; you; they; people (indefinite pronoun; construed as a third-person singular).
Imagine I came to your house, and photocopied all your documents.
Don’t worry, I blanked out the name, so it’s completely anonymous, and everything is where it used to be.
Would you be okay with that?
I certainly wouldn’t.
Making this opt-in or opt-out is a question of consent, and choosing opt-out shows that you don’t give a flying fuck about me, and only want your own benefit.