Why would Landa make the rat squirrel comparison?

Plenty of reasons to hate Jews, but Tarantino would never put it in the movie. I think he tried way too hard to make the Nazis look irrational and uncivilized in this fictional universe.

I took it as him saying that everybody in Europe hates Jews just as everybody hates rats.

The Germans compared the Jews to Rats quite often with their propaganda and had posters plastered all over the place indicating so,
https://qph.fs.quoracdn.net/main-qimg-9439446478bd0cad26dc51783dded207