The AR is the most reconizable weapon in the Halo universe... Sure, the battle rifle is the better weapon, but most people (people who know about halo and those who don't. My Aunt knows what gun the AR is from) sees the AR as Halo's signature weapon, much like how the Lancer is for Gears of War. This is mostly due to its design, as to where the BR looks like a real life weapon being used today. As said before, its Iconic.