That is very weird for a shock to break. Typically that is due to reaching the mechanical limits of the shock (topping or bottoming out). I have run Bilstein's in 17 different vehicles and have never broken one, nor have I broken a shock in any of the 59 vehicles I have owned.
I've never broken shocks on anything except this truck. I have triple-checked the limits and I am not bottoming them out; the axle hits the bump-stops before hitting the bottom of the shocks. They do "top out" if I am flexing hard enough to lift a wheel, but that is also the case in my 4runner and I've never had a problem there.
The shocks are a "universal fit" part number so rather than weld the eyelets on, they are threaded onto the shock piston shaft. I've never seen this on any other "specific application" shocks. The shocks don't actually "break," rather, the shaft unthreads from the eyelet over time and vibration. It seems like a manufacturing issue. I've been able to reassemble them on occasion and put Loctite on the threads, but this doesn't seem like something I should have to do.