Well it is with the family members of mine that were here during the occupation.
I have never met or spoken to anyone who is still sore about it and I have family who lived here during the time.
They arrived, met zero opposition and the islands were occupied. We were liberated. Yes occupied, but it was no war zone. Some people live in countries with more oppression from others/governments than Channel Islanders got from the Germans.
Well if you suddenly lost your freedom I think you'd soon change your mind, even if occupation was not too heavy handed. Of course people suffer worse but that's a bit of a mute point as you could argue that point on anything.
I'm not too up on Jersey history but people were killed in Guernsey and although most of the Germans that occupied Guernsey were actually quite nice, there were some very unpleasant officers as well. There were at least two air raids that I am aware of, both involving local deaths.
My Grandmother had her house taken over by 18 Germans and although they were very nice, near the end of the war the Germans took most of the food available and left the locals hungry.
My father-in-law lost several years of his childhood to live with strangers, although he had a great family there were many that weren't so fortunate.
I'm not saying those I know that are bitter about the war are anti-German or anti-British, but I do know many felt UK could have done more for what was a quite strategic piece of land for both sides, let down would be the term I'd use.
Everyone in Alderney for example were evacuated and a concentration camp was setup there - having to leave your Island and land/homes taken over would be annoying to say the least. Justification for feeling let down I'd say.
Off topic I know but thought I'd make my point.