Actually not. While it certainly wasn't common then it could happen you wanted to trash your opponent a little bit more before peace. I seem to remember that some of the Danish/Swedish wars went on a bit longer than they could have due to just wanting to siege this fort/take this area.
And during the 30 years war the Germans stayed and trashed Jutland far after we were fully beaten. In fact Jutland was so trashed that it was a factor when we 30 years later lost Skåneland. With a Jutland not getting completely trashed from the 1623 German invasion we might have retained Skåneland.
Also the Germans trashed the village my ancestors lived in and cost them lots of property to which I say: Pay denbts now!