I believe the fundamental difference is that the time to get to null-sec in EVE (the actual interesting component of the game that generates strong narratives) takes a significant time investment from the player. Leveling up skills, purchasing ships, and developing knowledge of the game are fairly tedious.

In comparison, you can get thrown into interesting situations from the get-go in DayZ. Basic FPS skills and a little knowledge of the clunky interface are all you need to generate strong player narratives. Whereas you make need several weeks to months to motivate an interesting experience in EvE, DayZ only requires a time investment of a couple hours (maybe).

I was going to say, it sounds like Eve. Except Eve isn't at all boring if you get deep into it, as in invested with a group in wars in 0-security space. Eve is one of those games that is lots of mundanity punctuated by sheer terror. I can easily believe that people who've played Eve have had (very mild) cases of PTSD.