To me it's the meaning behind the symbol. My question would be why would you need to put real military unit/rank insignias on yourself? To what purpose is that?
For shits and giggles let's use Navy SEALs. You can pretty much create an entire loadout from say "Lone Survivor". I like Danny Dietz so I create a whole look based on him in the film. Will I go so far to put his unit/rank and say even name on my kit? How does that sound? Sure, honouring him by playing airsoft as him? To me it just strikes a bad cord.
We're playing toy soldiers shooting plastic BBs for entertainment, some people are real soldiers putting themselves in harms way to defend our freedom... to me that's the big difference. I know if I dressed up as Danny Dietz that someone out there would be offended I'm "playing" as him.
That's all I need to know.