> because it is not from Mozilla and includes patches to remove propietary bits

More specifically, because Mozilla won’t allow you to do that and still call it Firefox. (Except if you’re Debian, apparently Debian now gets an unwritten free pass after they demonstrated their willingness to protest that with Iceweasel. And either F-Droid is not big enough for that, Mozilla is not the same as it was back then, or both.)

fdroid have a non political policy. arch is the same. they won't even patch things nobody like (just document on the wiki and keep building upstream with the least amount of changes from the code repo. even if the upstream maintainers themselves dont build like that)

so, if firefox build builds as fenec by default, fennec it is.