In many places the timber rattler is protected and often endangered. They only reproduce every 2 (rarely) to 4 years or more and the females only start to reproduce at age 6 to 12 years, depending on where they are located, so over population of their habitat is unlikely. Simply killing a rattler, or any snake for that matter, just because it's a snake is obscene and inhumane, not to mention probably illegal.
I like snakes and other reptiles and have had experience with eastern Diamondbacks, canebrake (a deep south, lowland race of the timber), pigmies, copperheads, cottonmouths and many species of nonvenomous snakes. I lived in Ga for 62 years. Timber rattlers were in the more mountainous region while we had the canebrake variety. They were all over the yard, in the barn, on my shooting range and on the porch. If I saw ANY snake in the road I'd always move it safely off whenever possible. Despite the scientific researchers assertions that canebrake venom was more toxic and increasing in toxicity for some reason, the snakes themselves were very docile. And the larger the snake gets, the more docile and sluggish they become. I found it extremely difficult to get either canebrakes or diamondbacks to strike. Copperheads, cottonmouths and pigmies, on the other hand, are very pugnacious. I had a dog bitten by a 3 ft copperhead and she had a really hard time of it. I caught it and had other copperheads in terrariums that I kept and studied before turning them loose in early fall in time for them to fatten up for hibernation.
True, the little pigmies have an especially potent venom but are so small they deliver only a small fraction of what the bigger snakes can deliver. But if bitten, you're in trouble. Of course more than half the bites from rattlers (and probably copperheads) are "dry bites", or no envenomation. These snakes are invaluable in the ecology of their territory; they, and others, keep us from being overrun by rats & mice.
I remain disgusted by these so called "roundups" and the cruelty and slaughter that occurs because of ego, greed and ignorance. Remember, we didn't create them so what justifies our destroying them. Be kind to critters that mean you no harm.