I don't think all of them are teenagers. There's at least that giant lady and the software engineer, oh and the slut. Which is why it makes no sense for the bus driver to wanna supervise them, but that's just an excuse. Remember how the bus driver got surprised by something before coming to the village? Something is up with that.

I think it's quite logical to prey on teenagers when doing a tour like this. They are at a sensitive age and easily swayed. If you're looking for much older people, they'd either be psychopaths or suicidal. Oh wait, even the kids are already like that. The two organizers are as shady as hell. They are too calm considering the situation.