Why are there so much adult people here?

This is a Subreddit for teens, but I think we can all see people in their 20s commenting on everything. Like, sure, seeing posts that are relatable is fine, but why DM? This really needs to stop because some of us are not comfortable with a 20-something person texting constantly.
P.S. Mods, this is not a rage bait, I think.I'm simply just concerned.