They are not in on it, neither are the manufacturers of "satellites."
Then the conspiracy theory is inherently flawed. It would be flawed the other way as well, but the point remains.
How exactly do you propose that this works? That somehow the 'industry' that manufactures GPS systems, creates charts and other navigational equipment is wholly isolated from the people that use them? Many times the people that create the equipment use said equipment, with those that initially use the equipment go on to make it later on in their careers?
Indeed, who are these people that do know? A selective cabal of scientists and businessmen that somehow shield the rest of us from finding out? Why would they do this? For money? You'd make
far more money exposing the truth than hiding it. The book deals alone could reach well into the billions if marketed right.
How does your conspiracy work exactly?