I think it’s very clearly inspired by - or even just a straight adaptation of - traditional Jewish music, especially the sort that appears in Fiddler on the Roof, a musical about the persecution of Jewish people in Tsarist Russia. (Edit: from this thread I have learned this is called Klezmer music, which would have made this faster to say if I had known)

It’s very intricate, lively, beautiful party music, and is so popular that it has been used as a shorthand motif to indicate Jewishness in all sorts of media. Just a very short sting will be enough for the audience to understand that what’s happening alongside it is connected to Jewishness in some way - positively or negatively.

So antisemites have used it as shorthand as well. The lively party aspect gets hatefully twisted into silliness and mockery, because if you don’t want to join the party it’s very easy to just say everybody else is wrong for having fun.

It really sounds like a traditional Jewish song. That’s my guess as to why this is happening.