For the most part, spies gather information and publish to a small audience. They are, essentially, doing journalism for a specific group and refraining from broader publication of their work.

I cannot remember ever reading the word "journalism" used to refer to the act of providing information to a small, closed audience. Publication is an essential part of journalism, not an afterthought. And nobody says that handing over a report to your superiors constitutes "publishing".

If I watch a wealthy couple having sex for my enjoyment, I'm a voyeur. If I tell a few friends, I'm a gossip. If I tell it to the absent partner of one of them, I'm a private eye. If I tell it to the readers of the Sun, I'm a journalist.

Wikipedia: "Journalism is the practice of investigation and reporting of events, issues, and trends to a broad audience."

M-W: (a) : the collection and editing of news for presentation through the media (b) : the public press (c) : an academic study concerned with the collection and editing of news or the management of a news medium

I agree that the practice of espionage and [investigative] journalism are pretty much identical when it comes to acquiring information. But what they then do with that information is very different and is, indeed, the very reason why two separate concepts exist in the first place.