Orbiter and the work of its community of add-on developers allows (but doesn't require) the user to learn at least the following aspects of "rocket science":
  - What sort of path a rocket should take to get from a launchpad to a stable orbit
  - What sort of maneuvers a spacecraft needs to use to change from one orbit to another, e.g. to rendezvous with another spacecraft
  - How to plan a mission to the Moon, or another body in the solar system
  - How to use the gravity of one planet to shape a trajectory to another, as Voyager did for its "Grand Tour"
  - The kind of systems a spacecraft needs, and their realistic or plausible capabilities
  - The sequence of stages to build something as complex as the ISS
  - Various ways that spacecraft (winged or not) can interact with a planet's atmosphere to manage energy during re-entry or on a fly-by
And all of this is free (as in beer), a precious gift from Dr. Martin Schweiger and the many other developers who have contributed uncounted hours of their time. See also the community's forum at orbiter-forum.com

In my book "The Making of 'I Saw Them Ride Away'" I mentioned the great help that Amazon, and their subsidiary CreateSpace, had been in enabling the publication of my Great-Grandfather's memoir. When I submitted the manuscript for format checking, it was rejected because it mentioned "amazon.com". I had to eliminate a very complimentary sentence, at their own insistence.

I'm sure the policy makes sense to someone.

When toys are outlawed, only outlaws will have toys.