I think it's the fact that War Thunder is less serious than hardcore sims that makes all the difference. The sort of person who is into a "real sim" and values the experience of reproducing the "real" experience is also relatively aware of the culture around military technology. You know it would be potentially bad for you to post classified stuff and you probably understand why "not for export" and "top secret" are different classes of information and why you want two classes of information. You respect the information hierarchy that these systems of secrecy respect - and part of that respect means you enjoy really flipping all of the knobs on an Apache. You probably have access to these documents but you would never be so gauche as to post them on a public forum.

On the other hand, if you mostly enjoy military hardware in a semiotic and arcade-y way, all official documents simply represent potential ammunition to win internet arguments. You aren't aware of the baroque system of different kinds of secrecy and if you heard of itt you would think it was silly. If the information is "out there" already why wouldn't you post it to settle an internet argument? Surely if you can get your hands on it then any potential enemy has as well.