This is basically it.

Imagine, for example, a case is about someone disclosing the location of nuclear arms to their spouse. Maybe even accidentally. If they are brought up on charges about this, national security doesn't want the fact that a case is about nuclear weapons to be public information. They further don't want it disclosed who was told about them (as the spouse wouldn't be subject to charges). That's basically where a secret interpretation and ruling would ultimately enter. The courts can't disclose what the ruling was nor what the case was even fully about.

From warrantless wiretapping to extra judicial renditions, the US government has been a rogue state for sometime. Now they just have low-grade criminals and racists running the show, buddied up with media owners, O&G and the mic.

I am the first generation out of a dictatorship, the belief some folks have in their democratic processes always amazes, there is no law when secret courts and secret warrants are a thing.

Yet for some strange reason folks think secret agencies are bound by the same laws as regular police officers.

Yeah but they are only targeting bad people, so it's OK.

I can get the idea that for some cases it can be in the public's interest if specific court hearings are closed, or if it's secret that certain court hearings or entire cases even exist. There is a lot of potential of abuse (and a documented history of abuse), but at least the idea makes sense

But I can't see a public benefit to keeping the principles such a court uses secret

It’s a pretty obvious outcome. Attorney-client privilege applies to the executive branch of the government as much as it applies to anyone else, and not just in national security matters.