My conspiracy theory is that all the adults died from a likely zombie invasion or something and the only survivors were those who could hide in a 1x1 block hole or something.
So this is like a dark side of Minecraft, zombie invasion, kids running and hiding, a horror story that needs to be told.
On a side note, with these Minecraft posts I might get myself a server and some RPG/Graphics modes this holiday and play it.
I love the freedom this sandbox game provides. You can choose your own path forward. Good luck with the new server if you decide to go for it. It is always exciting to start a new playthrough.