Have you considered creating your own, customized Atomic image which doesn’t include Firefox? Since you’re obviously not an “average user,” that shouldn’t be a big deal, right?
There are even tools that help with that:
Fedora Atomic: A simple guide to creating a custom, local bootc image
I’m guessing there are other methods/tools for doing so out there as well. The above were just the first three results in a DuckDuckGo search for “Fedora atomic create new image.”
I’m sure that if there’s enough interest such custom images would be very popular.
That’s what open source/libre software is all about. Don’t like how those Fedora packagers are scheming with Mozilla to further [whatever evil plot those Mozillans want to unleash on the world – perhaps just as innocent dupes – or perhaps not]? You can save us all!
You have the power to do so. I suggest you use it.
I expect that it would take less time and effort to create a Mozilla-free (don’t forget about Thunderbird. Those folks probably put that in the default image too!) Atomic image than it would take to successfully lobby the packagers to do so for everyone else.
Whether you create your own image(s) or convince the packagers to change the default image, I wish you luck and success in all your endeavors!