Dark RP only for kids?

The majority of the playerbase inside of Garry's Mod are usually teens, some kids, and very few are above the age of 25. It's debatable on whether DarkRP is a childish gamemode or not, since it usually depends on what server its on. The concept of it is great, roleplay without anything to go off of (like millitaryrp, for example), but some servers execute it in different ways which can be either great or vastly horrible. I've been on both sides, so I believe I can back this up with personal experience.