I was reading Kafka's "Josefine, die Sängerin oder das Volk der Mäuse" and came across this sentence:

Schon deshalb nicht, weil sich hier das Volk in seiner kalten richterlichen Haltung zeigt, wie man es sonst bei uns nur sehr selten sieht.

I understand the weil clause well enough, but the "Schon deshalb nicht, weil..." construction as a whole has me confused about its logic. Willa and Edwin Muir translate it as "Just because of the fact that..." and similarly when I put it in DeepL or Google Translate, it's translated as "If only because..." I understand that the meaning of schon in this context is similar to that of bloß and the construction deshalb, weil essentially means "That's because..." or "For the reason that..." So Schon deshalb, weil... alone would also mean "Just because of the fact that..." and DeepL also translates that as "If only because..." But what is the function of nicht? How does this whole construction make sense?

I was reading Kafka's "Josefine, die Sängerin oder das Volk der Mäuse" and came across this sentence:

Aber sie hat keine Feinde, und selbst wenn mancher hie und da Einwände gegen sie hat, dieser Kampf belustigt niemanden. Schon deshalb nicht, weil sich hier das Volk in seiner kalten richterlichen Haltung zeigt, wie man es sonst bei uns nur sehr selten sieht. (Wikisource)

I understand the weil clause well enough, but the "Schon deshalb nicht, weil..." construction as a whole has me confused about its logic. Willa and Edwin Muir translate it as "Just because of the fact that..." and similarly when I put it in DeepL or Google Translate, it's translated as "If only because..." I understand that the meaning of schon in this context is similar to that of bloß and the construction deshalb, weil essentially means "That's because..." or "For the reason that..." So Schon deshalb, weil... alone would also mean "Just because of the fact that..." and DeepL also translates that as "If only because..." But what is the function of nicht? How does this whole construction make sense?