That's a good point. And there are ways to save weight without carrying a lighter rifle. Gear, pack and what's in it matter too. Besides, I'm willing to bet I'm not the only one that could shed some weight off my middle and save WAY more than a few ounces.
Do you carry your belly in your hands? How about the stuff in your pack?
Your rifle is the only item which you carry in your hands while hunting and stuff carried in your hands is supported by your muscles. 8oz in your hands is likely the equivalent of 15lbs in your pack.
Neither is carried in my hands. But at the end of a long day of hiking around northern NH mountains which I do every deer season (no, they aren't 10k footers but none the less) I can tell you, I'd do better shedding 10 or 15 lbs of body mass then carrying around 8oz less rifle.
It's not to say that a light rifle isn't better for some. But I'm not opposed to carrying around my 8+ lb Winchester if that's what I want to do. And I've carried it all day, from before sunrise to after sunset (many many times), in my hands.
And what's tired at the end of the day? I'll tell you what, it isn't my hands or my arms from carrying an 8lb rifle. It's my legs. Your legs are what tote you up and down mountains, not your arms and your legs have to carry ALL your weight no matter where it is.
