I suspect it's been cut. Either that, or it's just meant to be a sort of "yeah, Moonhaven was always kinda fucked, between the swamp hag, incognito Red Wizard and Underdark entrance right next to the water source, not exactly safe for children." :P
Maybe once upon a time they were part of some sidequest connected to Ethel, the Red Wizard or the invading Sharrans, or maybe it was just atmosphere, who knows. /shurg