It is a pretty lucrative GOTCHA!
Edit: and win
Here is a guide on the US tort framework for libel and slander
https://www.nolo.com/legal-encyclopedia/defamation-law-made-...
You can also be sued by the state under criminal statutes for defamation and this is constitutionally protected under several circumstances that are broad
https://en.m.wikipedia.org/wiki/United_States_defamation_law
So people have just made up a social contract about the US that doesnt always exist. This is partially because the definitions vary from state to state, and judge to judge within a single state. But you have to also realize that other countries are often structured the same way.
Tl:dr; many people’s experience in the US is one where there is both civil and criminal liability for making fun of someone and it has always been like this. Just like “those other worse” countries, no matter what your childhood indoctrination convinced you of.