I've lived in Arizona for 25 years and spend a LOT of time outdoors between hunting, scouting, hiking, mountain biking, riding motocross, and riding ATVs. I've seen easily 250 rattlesnakes in the desert. Shoot, one quail season opener, we saw more rattle snakes in one day than we saw birds. Never been bit thankfully. What I learned pretty early on is, western diamondbacks are very docile. In fact, they are amazing docile, until you mess with them. They are not aggressive at all, until you piss them off. Most people that get bit either step on them or are messing with them. I tell people they aren't aggressive, they're defensive. I'll bet <90% of the rattlers I have come across didn't rattle unless I messed with them. A lot of snake bites from rattlers are dry bites, so if bitten try not to panic - just stay hydrated and get to a hospital. I also keep benadryl in my packs cause I have no idea if I'll have an allergic reaction - good for scorpions too. I've been inches away from dozens of D'backs. I always wear nice hiking/hunting boots (Asolo's) and when hunting I wear snake gators - mainly to help keep the cholla needles out of my legs. From my experience, if a cholla needle won't go through it, chances are a snake bit will have a pretty hard time penetrating it too. Cholla needles are freaking gnarly.
Have one buddy who got bit when hunting alone. One fang went through the hole in his cowboy boot and the other didn't penetrate the leather. The strike ended up being a dry bite. His dog got the snake fired up and he ended up stepping on the snake by accident.