You didn't answer my question about what is not allowed to be challenged.

>Yes, in communities that try to claim that certain things are "political" and certain things are "not political", "banning cryptocurrency" could be rejected on the basis that it is "political". The point is that saying something like "we don't do politics" is absurd.

I don't understand what you're saying. You switched tracked halfway through the thought from talking about communities that distinguish between things that are or aren't political to rejection of taking political stances.

What is usually meant by "we don't do politics" is that an institution or organization will avoid picking sides on political issues. This is not merely not absurd, but pretty much necessary for any organization that doesn't have ideological goals and doesn't want to foster internal factions.

Like the sibling comment said, just banning cryptocurrency might be political or it might not, depending on the reason for it. Rejecting reasons such as "crypto bad" is a tenable position if an organization seeks to maintain a neutral stance.