Because that's not the reason (Israel primarily imports weaponry and munitions from the US and India [0]).
The issue is the other way around. A significant portion of Germany's ground AD and defensive systems are sourced from Israel- most notably the Arrow 3 missile shield [1] deal that recently went through. Germany is heavily dependent on Israeli cybersecurity companies as well [2]. Germany is also subsidizing Arrow 3 sales to Ukraine [3].
Protecting your nations citizens always trumps morality, and in Germany's case, it's become even more critical after what happened in Poland this week.
[0] - https://oec.world/en/visualize/tree_map/hs17/import/isr/show...
[1] - https://www.defensenews.com/global/europe/2025/06/09/israel-...
[2] - https://www.reuters.com/business/aerospace-defense/germany-s...
[3] - https://www.wsj.com/world/europe/israel-sells-missiles-to-ge...