It’s probably a similar reason to why the european country that first asked for sanctions againat Israel was the Republic of Ireland, who like Palestine and until the early XX Century was occupied and oppressed by a larger neighbhour, in their case the United Kingdom: when you suffered it yourself or grew up hearing the stories from those who suffered it, it’s a lot easier to understand the true depth and hurt of what’s being done to a people in a similar situation as you, your paraents or even grandparents were once in.

It also explains why Germany still unwaveringly supports Israel: they naturally empathise with the strong military power that’s trying to control a “lesser race” in a territory they occupy - it’s painfully obvious that “never again” wasn’t at all about the violent genocide of a weaker ethnic group by a stronger one driven by cold violent extreme racism (the kind who describes another etnic group as untermenschen/human animals) and greed, but was only ever about Germans vs Jews, hence Germany ending up again involved in a Holocaust on the side of the genociders.