While I don't think any Scot would qualify the massacre of Glencoe as a "little incident", and while, as a German, I believe and have to believe that we must never forget the past, I also think that we can learn from it and that today's generations can not be held responsible for what happened long ago.
When my German father married my French mother in 1962, the war had not even been over for 20 years. It was a great shock to both families. I did get the odd remark as a child during my holidays in France ("you killed the Jews!"), a swastika was drawn into the dust on my German car while on a uni exchange to England in the 1980s, but today, the friendship between France and Germany is such that there are many, many French-German couples and the "hereditary enemy" is not that anymore. I have now lived in France for 25 years and have not experienced any nationalist comments during that time.
If people in our educated, well-informed society can't overcome a war that took place 150 years back, then the only thing I feel for their stupidity is pity....