Stefan, while I appreciate your viewpoint, maybe you can answer a short question after your prologue.

How exactly is your experience or even your installation harmed when other guys install weapons, scenery or something else to their PCs?
And maybe an additional one.
How is this global "peace" influenced if you or somebody else installs weapons or anything related to it into his simulator?

Do you think the game changed because you can shoot now? I could bet that your FSX installation still is the same and always will be until you change something in it. So your freedom isn't harmed at all while this strict "please develop something else" appeal actually does harm the freedom of other guys.  ;)
So one part of this peace you may be talking about should be the freedom to actually chose if you buy, use or like stuff, doesn't it?
We're talking about a simulator here, nothing which influences other people's lives, so the moral aspect of weapons in this thing is very weak in my eyes and shouldn't be stressed too much since this is just a game.