I think it's proof that given sufficient decorative fluff, people will spend a great deal of time attempting to make sense of nonsense. Same basic principle as snake oil.

No, it's proof that properly executed steganography works.

http://en.wikipedia.org/wiki/Steganography

No, it's proof that no one can crack what's just random shit pasted together. No message, no decoding.

Why would you assume there's a message behind the Voynich?