An airsoft impression is just that - an impression. The context is an impression and not an impersonation. And of a foreign military to boot.
On the other hand, wearing US insignia can be different outside of an airsoft game venue...
Me at 16 years old on post at Ft. Lewis, wearing civvies with a jungle jacket, completely tabbed out airborne, ranger, jump wings, etc etc:
Grizzled veteran: "Where did you get your jump wings?"
Me the snot nosed kid: "um, AAFES." (That's the Post Exchange).
Grizzled veteran, expecting that I would have said where did I EARN my jump wings (like at Benning): A look of complete and utter contempt.
Me the snot nosed kid: Feeling 2 inches tall.
Grizzled veteran: "You might not want to wear that around here. Guys that earn those (pointing at all my high speed insignia) might not like you wearing it if you didn't earn it." Duh.
And I never forgot that. I could also tell by his ribbons that he'd been to Vietnam. His CIB and 9th ID patch on his right shoulder told me he had seen combat. Lucky I didn't get my a$$ kicked. Or get scooped up by the MP's.
Live and learn...

"He has all the virtues I dislike and none of the vices I admire." - Winston Churchill