Red Bull is honestly not that popular in this crowd though, the major energy drinks you see are Monster, Rockstar, and as mentioned, Rip It (really an offbrand of the former two from the maker of Shasta/La Croix). These typically have 160mg of caffeine, which is high for coffee although not by a large margin. The culture around them seems to encourage much greater consumption though, with oversize cans (e.g. 24oz with over 250mg caffeine) not unusual and many people having multiple drinks a day. It does seem like something about them, perhaps the addition of a great amount of sugar, encourages more consumption.
I'm also a little confused by your accusation, since the article discusses a comparative study of two groups, both in a warzone, and finds increased mental health effects in the group with higher caffeine consumption. No one is denying that combat conditions contribute to adverse mental health effects, but the whole point of the article is that these seem to be exacerbated by caffeine use.
Sleep deprivation is becoming a real concern in multiple military branches, and I suspect that the mental impact is not due to the caffeine per se but due to the culture around it: consumption of hundreds of mg of caffeine is viewed as an acceptable alternative to sleep. This is definitely also an issue with coffee, but energy drinks seem to be predominant today.