Systems that are just do not generally require secrecy to the degree that unjust systems do, precisely due to the fact that when publicized, people will generally agree with just processes.

Except that even a just system has parts that can be taken out of context, and twisted to paint a narrative that it is not just.

There are a whole bunch of examples of this, though "hide the decline" sticks out to me.

It's also the justification for keeping courts open to public attendance but barring recording equipment (in Canada).

That's why I said "to the same degree", i.e. privacy is important, but you don't have to have the massive opacity required for large-scale unfairness to persist.