So true, but you know what I'd like to see as an incentive to continue having builders -- have the huts, dam, briars and vines on a timer. At a certain predetermined amount of time, the huts could start showing disrepair and if a villager or villagers don't start fixing them, they would fall apart only to need to be rebuilt.

The dam could need some mending as the wood used would become unstable; thus, needing attention.

The briars and vines would still grow and need to be thinned out from time to time like our gardens.