The baker can shun the gay couple, the Nazis can spend their time and angst declaring under a cover of "Free speech is a human right" that all other ethno-religious groups are sub-human and unworthy of rights, and a reasonable human can decide to shun them both as utterly ridiculous.

If that reasonable human runs an open source app store, more power to them.

Intolerance of intolerance promotes tolerance, and F-Droid isn't the US government.