User blog comment:SomeoneYouUsedToKnow/SYUTK's V4E10 - Guroyuri - Impressions/Recap/@comment-25405817-20170124025735

About the level of ruination of the village, remember that Grimm are capable of learning. It is a fact that any settlement that is left abandonned, with no attempts of keeping maintenance, gets eventually overrun by nature. Thus, a Grimm wouldn't need to waste energy to bring down every building, if it can just let time do its work.

That, or it could also be used by some Grimm to trick humans into a fake sense of safety.