@wolf480pl @cjd I don't think I care how it came to be. It was the elephant in the room all along because similar things have happened to feed readers and podcast players. I think it is important that Play Store rules are changed so that apps that work by letting the user configure where to connect to are not held responsible for user-generated content, period.
@Gargron @cjd Yes, that is the bigger problem here.
Even if Google had no ill will in blocking those clients, its policies - assuming they indeed require server-agnostic apps to moderate content - are misguided at best. It would be good if we persuaded Google to change them.
One way to do it I think is to report Google Chrome as violating the same policies. I don't know if it's a good way, but it sounds fun and it's the only one I can think of.