My point is that the letter of the First Amendment and the spirit of the First Amendment are at odds when faced with modern day reality. Between government and corporations, and being fined, vs being put in prison, it's all up for debate. We can look at the letter of the First Amendment and twist and turn it to come to a definition that the courts can agree on, but stepping back from that, the bigger picture is the people are trying to speak and that this entity that isn't the government, is restricting that, with downstream effects. You're right that the First Amendment doesn't apply to app stores run by a private corporation. It's still a restriction on speech by a large organization against an individual, and the freedom of speech gives people the right to complain about it.

If you were talking about Apple or Google, you might have a point, although you would be better off to talk about "freedom of speech", since "the First Amendment" refers to a very specific piece of legal text (and one that nobody has actually ever said should apply to app stores).

But we're talking about F-Droid here. It has a tiny market share. It uses software that lets literally anybody else set up a repository and have it appear integrated in the same app. It doesn't benefit from any of the legal or social advantages given to large corporations. F-Droid, unlike Apple or Google, can't in fact do much to limit anybody's speech.

It's fair to point out fdroid's drastically smaller market share, but in an effort to avoid"meet the new boss, same as the old.boss" I still think it's worthwhile to point out the levers of power and systems involved.