Do you also dislike stories with talking animals because animals can't talk?
It's a parable, and you seem to be taking it too literally and simultaneously not literally enough.

On the one hand, it's saying not to trust people who want to hurt you even if your interests are aligned. The soviets trusting the Nazis not to attack them just because they both gained by dividing eastern Europe and not fighting a war on multiple fronts. No amount of shared interest will keep a fascist from hating a communist.

On the other hand, you actually really shouldn't put scorpions on your back. It's actually fine to reduce the agency of an insect to a stereotype of their biology.

Not sure why you'd getting downvoted here but it's absolutely been used (a lot) to push racist ideas. I first heard it from an antisemite.

I think it's just a shit message - "people will betray you on surprising ways, trust no one"