Confused about "Schon deshalb nicht, weil..." construction

Question

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?

Answer 1

The relevant part of the quote from Josefine, die Sängerin oder Das Volk der Mäuse or Josephine the Singer, or the Mouse Folk is

(...) dieser Kampf belustigt niemanden. Schon deshalb nicht, weil (...).

As David Vogt noted in the comments to your question, the phrase "schon deshalb nicht" refers back to the previous sentence. You could combine the two and get

Aber dieser Kampf belustigt schon deshalb niemanden, weil (...).

So the combined sentence describes the main reason why this fight doesn't amuse anybody. Even if there were no other reasons, because of that this fight still wouldn't amuse anybody.

An English equivalent would be

But this fight amuses nobody, if only for the reason that (...).

In German, in contrast to English, the negation of the first sentence gets "repeated" in the second one. A assertive example could be something like

Aber dieser Kampf belustigt die Zuschauer. Schon deshalb, weil die Kombattanten mehr über die eigenen Füße stolpern als dass sie den Gegner treffen.

Answer 2

I just loosely translate and hope it helps.

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.

But she doesn't have any enemies, and even though some now and then object her, this is no fight anyone would look forward to. If not for any other reason, then because it shows the cold judging streak in people in a way otherwise rarely ever seen among us here.

Edit: This shows the "nicht" in "Schon deshalb nicht" relates to the "nie" in "niemanden" meaning 'nicht jemanden' like in nobody.

"Schon deshalb (nicht), weil..." translates as "If not for any other reason, then because..." in a similar way.