> Discussion is terribly confused when 'censorship' is interpreted in this general sense.
It's the original sense.
> Censorship enforced by the state is something distinctly different from editorial control exercised by private entities.
Yes, government censorship is different in important ways than censorship by a publishing or distributing entity, but both are censorship (and they are also similar in important ways.)
> When the single word can represent either concept (and other related concepts) ambiguity and confusion isn't far behind.
Heavy water is different from drinking water in some quite important ways, but its not at all a problem that both are identified with the word "water", because we can use more than one word when the differentiating features are important to the discussion.
> I used to argue that 'censorship' should be interpreted as something done by governments and enforced by the legal system but that battle has been lost.
That battle was lost centuries ago. What the censor librorum does in granting, or denying, the nihil obstat has always been censorship, even where the Catholic Church is not an established Church and so is in now way part of the government.
> Now the unqualified 'censorship' can mean just about any sort of content restrictions and as such is almost useless in its unqualified form.
It has pretty much always meant that, and just because the general sense of censorship is not something you are interested in talking about doesn't mean it's not useful.