I feel like a good number of people have been in a fight or two, or wrestled in highschool, did some backyard boxing at some point, practice BJJ ect.
None of those things are MMA, but it does fundamentally put you in the same position as a fighter. I thing the average person can relate more to what actual MMA feels like MUCH MUCH more than what war feels like, and game companies still try to make "Authentic" war games such as ARMA.
I've seen this argument float around here a couple of times and it seems odd to me.