The guilt-tripping began with the Germans, but it eventually engulfed the entire continent.
Britain, France, Holland, Spain and others are guilty of colonialism. The Crusades and Inquisition hurt Muslims and Jews.
In truth, everyone hurt everyone throughout history, but the focus post-WW2 has been on "white European Christian patriarchal hetero-normative" societies.
That’s far from the only thing the Germans have done wrong.
Historically, Germans have been no worse than anyone else. Napoleon waged war on most of Europe only a century before the Great War.