"It seems that anyone hiking as frequently and/or for as many miles as it would take to learn to cut unnecessary weight would find themselves conditioned enough that an extra two pounds for a gun and ammo isn't going to lead to a broken back."
Well, I've spent a couple of months a year hiking in the Rockies for over 30 years. And by hiking I mean a ten plus miles a day, much of it off trail, at over ten thousand feet, for up to two weeks. Let's say my wife and 11 year old nephew are along. It takes close to two pounds of food per person per day. Six times 14 means there is 84 pounds of food to carry. And maybe 20 lbs of personal/group gear per person - these are high mountains where you can get a foot of snow in mid august, so you want some warm clothes etc. Keep in mind that you can't put 80 pounds in your 24 oz. ultralight pack; just the empty pack is going to weigh 6 or 7 pounds.
For some reason we don't divide the weight evenly, so I'm carrying 75 or 80 pounds. That's OK; I'm used to it. But I also know that every pound matters. I've heard novices say that 'past 50 pounds it just doesn't matter'. IMHE that's not true - how far and fast you can travel is directly proportional to how much you are carrying. I'm trying to enjoy the trip, not build character. And so you're looking to pare every possible pound - and that means you have tough choices. Take the gun? Pare the food and risk spending a few days on half rations? Take the light tent and make sure you don't camp high in a windstorm? Leave the camera? Skimp on the first aid kit? Leave the parka home and hope for good weather? Leave the ice axe and hope the passes have melted enough? Etc, etc, ad infinitum.
There just isn't any 'extra two pounds'. You're always skating on the edge of eating uncooked macaroni because you ran out of fuel or eating nothing because you ran out of food or shivering because you brought the 20 degree bag and the temp dropped. That's why people are so obsessed on light weight - if stove A and stove B both work but one is a pound lighter, that's an extra pile jacket, or a little more distance each day. You're always looking for the same performance for little less weight - because then you can go farther/faster/longer.
That's why I like the 329
.
If your hike is an overnight 5 miles to the lake, well heck, by all means carry the air mattresses and the bottle of wine! But the longer you go, the more weight matters.