I could certainly lose a couple pounds, but from the hiking & backpacking I do in the mountains, and the hunting I do in the fall, there's not too many people that can 'out-walk' me. There are some, but not too many.
I certainly appreciate a lightweight rifle, because even if I lose a couple pounds off my gut, that doesn't stop my shoulder from aching after a long day of walking/hiking. When the rifle gets over 7.5 lbs scoped, then after only about 4 hours of walking, my shoulders start to complain.
But if you're not the type of hunter that walks all day [and there's nothing wrong with that] then you don't won't see the need for a light rifle.