While it's not for me, I have done reenactment (swords and axe stylee) and I can see why folk would enjoy shining their buttons regulation style. No problems, play dress up the way you want to play dress up. The OP video's two real complaints are:
1) "Stolen valour", and I can see why that would piss off serving and veteran military if they spot someone wearing contemporary insignia. Contrast with Lindybeige on YouTube who has deliberately chosen a set of
costume medal ribbons that couldn't possibly represent a real service record.
2) Trying to make other people into bit part players in your dress up story. Annoying to everyone, although perhaps easier to laugh off.
Actually, we had a right Shouty McLeader at CQB last time I was out, all "Right, you lot with me! Move!" and "Breach! Breach! Breach!" The more folk just ignored him, the more strident he got, until he packed it in sometime after lunch. I guess it was funny in isolation, although I can see why it would get less so if it were a whole squad giving it Billy Bigguns all day and re-enforcing each others' delusions.