[hurbledr]

Actually, several developers have stated as much, most notably Thomas Biskup, who develops Ancient Domains of Mystery.

That's not to say you're wrong on any of your other points, but I think the reasoning for it isn't so much to prevent players from figuring stuff out and publishing guides, but more to encourage players to experiment and figure stuff out for themselves rather than relying on a guide to tell them the 'right' way to do things.