A couple of thoughts here: you're assuming everyone is only going to shoot 1 oz. loads? The 12 can be loaded down to 7/8th shot, no problem. The 20 can be loaded up to 1 1/4 shot, no problem. However, the 20 can't be loaded up to 2 oz hunting loads and the 12 can. Also, the weight of the gun absorbs much of the recoil. Many shooters like the extra weight when shooting clay target sports and some recoil sensitive people like the extra weight also. "all the extra weight of a 12 ga is kind of meaningless when a 12 can actually weigh less than some 20ga guns, and some 20ga guns can weight more than some 12 ga guns. You really need to learn more about shotguns, shot charges, and the differences in what they are used for. FWIW, simply getting a lighter pair of boots can save the difference in weight of the shotguns. The gun isn't the only thing you're toting around all day. At the end of the day, no one says you can't choose either based on your knowledge and applications.