Actually, it's more than just a multiplayer skin. The campaign takes place in the "real" middle east, putting you in the shoes of "real" military operators up against "real" taliban. The plot is fictional of course, but it does use some true to life elements.
If people think a game is offensive or insulting, they generally don't buy it. Who's going to bury a lost family member and subsequently play Medal of Honor, drink a few beers, etc.? Gaming is a form of entertainment, and as the statistics show, most people that play games like Medal of Honor are old enough to understand what war is and the sacrifices being made by military forces around the world.