How much time and effort may have been put in?

[eggyk]

And likewise I never cared about research that assumes a complicated cipher that not even the NSA and Bletchley spooks could crack.  What would be the point?  If the Author was terrified by the possibility of certain parties reading the contents, he should not have filled the book with puzzling diagrams and exotic scenery. In fact, he should not have written the book at all...

This gets to the very heart of why I asked the question. There are many presumptions within this answer, namely that there must have been a purpose, and that whoever wrote it must have been terrified of the contents being read. Who says there has to be a point? As I said, people do very difficult things with no point to them all of the time.

Imagine an artist with a private sketchbook, within which they spend a long time creating detailed sketches for no reason other than to practice or for enjoyment. Perhaps in that case the reverse question is more relevant: Why would they spend their time quickly scribbling low quality easy drawings, instead of practising more difficult detailed sketches? 

Obviously in the case of the VMS it would be a cipher enthusiast instead, but hopefully what I mean is clear..