[lorenzhs]

Yeah, I'd assume the point would have been not to be found in the first place (otherwise, why hide the entrance?) and to be able to defend against attackers if they do find you but didn't think of just letting you suffocate in there or smoke you out. In that case, you'd probably have a better chance of survival in an Erdstall than pretty much anywhere else, right? The scenario might be a bit contrived though (wouldn't attackers pick up on the "just let them suffocate" tactic rather quickly?), but then again if the explanation were on hand then there wouldn't be a mystery to debate :)