I think an issue is comparing one action and using it as the norm on the Western Front. Point to the French, Danish, Norwegian, or Belgian town that suffered a similar fate? Many of these regions did suffer from stopping food shipments, killing civilians in response to partisan action. Nazi's are bastards pure and simple but the Black and Tan's as well as the Aux of the RIC responded in a violent heavy handed manner to any action done against the government.
I am not saying all of England did this, nor am I saying the Nazi's had a feather touch to their occupation duties. I am however saying that Ireland is hardly unused to occupation by a determined force which is not above killing innocents in response to actions against its own.