I will shoot at anything that represents anything that includes my self except human babies.  I will not shoot at anything that looks like a baby.  Babies are off limits for shooters.  Except in horror games where babies are monsters.  Like that little monster baby creature in witcher 3 that was the Barons dead offspring.  Killed that thing.  

what about American zombies from mars in the forest?
 
I do wonder how you can really define what an American even looks like, given the melting pot diversity the US has, stereotypes are less meaningful than they might be in some other countries (though my knowledge of demographics is admitted limited)
it may have to do with how we empathize with others, the closer they are to you, the more you empathize, one may empathize with your family more that strangers, humans more than pet animals, pets animals more than insects. though to what degree one should fight that instinct, may not be universally agreed upon.
 
... hmm went off on a philosophical monologue there...

I interpret it as an attack on rural America, not on Americans as a whole. Urban dwellers will probably love this game with how divisive people are now a days.

Some people just get upset over the most ridiculous things! For crying out loud! IT'S JUST A GAME!