I've come across a lot of rattlesnakes over the years, and just haven't had any desire to kill them I guess.
I travel with a pistol in the truck and keep one in camp. If I'm rifle hunting I don't see the point of carrying another gun specifically for bear and lion defense. Due to my job not allowing time off in September I only archery hunt locally, and we don't have bears here. Lions and lion attacks are scarce enough that I'm willing to take my chances on them.
I carry a pistol all the time, archery hunt rattlesnake country a lot, and have never had to shoot a snake. See a bunch, but like you I never shoot them. I like to think they are helping to keep the competition away.