The license agreement for Visual Studio .NET specifically forbids you from developing a product that significantly duplicates the features of Microsoft Access.

Then again, there is nothing stopping Microsoft from taking the best programs developed for their OS and using it themselves, with the significant exception that they gave that right up long ago in the interest of getting more developers for the platform. Same with Apple.

Blizzard have given you a game and wilfully developed an API for said game so that addon authors can do stuff that Blizzard hadn't thought of. Some addons have been banned and Blizzard have made changes to the API to prevent in-game character automation (think Glider but in-game). These are the rules that addon authors live by. Despite the fact that the Lua source code to your addon is freely visible and only mentions WoW API functions, the addon author is still using Blizzard's IP and trying to charge for it. Unless Blizzard have confered those rights to the addon authors (and I haven't seen any license agreement that says they do), you are using their IP and the addon authors do not have the right to profit from it.

Who would have thought the real prudes wouldn't be over zealous religious players and instead dowdy old government goons

It was a court finding, not a parliamentary decision.