Unfortunately, in rural environments you can't let dangerous snakes live around valuable stock, and I'd wager that most people don't know enough to relocate them safely (I'm not sure I do) and so killing them is the best method.
Where I grew up in the hills, it was an hour to the nearest hospital and all of us kids ran around barefoot. That meant that copperheads around the house got killed, unquestionably. We all knew how to recognize them from an early age, and it was just the way things were. They afforded me some interesting dissection opportunities as a budding scientist...one that we found in an old tin pile had eaten two skinks and an Eastern fence lizard. I had always assumed that mammals were their primary diet.

So anyway...all other species were left alone (well more likely, we caught them and looked at them and then released them) and the big black snakes that found their way into the chicken coop were relocated to a neighbor's barn.

But the ones that could harm a child or the livestock and were in the areas around the house, well they had to go. Outside of the pasture, we left them alone...did you know copperheads also eat fish? I got to watch one kill and eat a shiner in the creek once.