Honestly, time. Time eventually changes things and Russia's occupation of Crimea was only a decade ago and the founding of Israel was like 80 years ago. Israel's continued expansion and settlement is wrong and comparable to Russia occupying Crimea.
Then why isn't Germany recognizing Palestine? Those people have been there quite a while.
Only the 75 year old Israel appears to enjoy existence for Germany. Of course supporting Israel's now open and blatant annexation of the West Bank and planned annexation of Gaza.
But the fact that they don't doesn't mean they shouldn't be actively opposing antisemitism in Germany. Opposing Israel's actions is different than "Israel shouldn't exist" because in the context of Germany and the neo mazid, not existing is literal and includes the people of Israel.