The secret is subtracted, but is not taken by someone else, unlike with theft. Instead it is destroyed. If you want to equate it to a physical crime, vandalism or criminal damage would seem to be a better fit.

Yes, if the information is simply published vandalism or sabotage would be a fitting category. But if it is sold to a third party it is more similar to theft. In any event, it's probably much more useful to have a separate legal concept for "piracy" that does justice to the specifics of digital goods and the way they are used.