I used Jack3D (with the DMAA I believe), No-Explode, Muscle tech/pharm and Rampage quite a bit in college and they sold it in large quantities on post. It was a great pick-me-up to a workout when you were tired or needed an extra pump. I used it solely with strength training and never in a military field training or cardio capacity. I also always brought a large gallon of water to the gym whenever I took any pre-workout. There will always be those who ignore warning labels and such but that doesn't mean a class of products needs to be demonized.
Protein powder and mass gainer are not gimmicks. If taken properly with a balanced diet you can surpass muscle gaining goals easily. They have been tested and proven very efficient for an athletes diet (especially a busy one). During my frosh year of ROTC I was 135 and during that summer I lifted hard with protein and mass gainer pushing me to 160. Currently I now sit at 5'11 185.
Many people who SERIOUSLY (and I am not talking ROTC or Ranger challenge type of workouts) lift in college or elsewhere take some sort of pre-workout. The key is moderation, hydration, gauging the intensity of workout and cyclical rotation of the supplement.
Just my opinion though, but I would venture to guess these soldiers used the product in a high high dose or had some underlying health issue. I knew guys who simply didn't cycle it and would be taking up to 5 scoops to get the effect and I would agree that is NOT healthy. The article suggest that the injuries and deaths occurred during field or physical training. Both training situations require at least moderate cardio which is a terrible idea to sustain a jacked up HR that's already elevated from the workout. It's not advantageous nor smart to use the product in this way...