People call Amethyst mean for laughing when peridot was insulting Steven and Garnet in Too Far but getting offended when peridot was insulting her, but in the beginning of the episode when Amethyst was laughing at peridot's jokes it was because they were strange. She called a screw driver a leverage optimizer. Amethyst laughed because it was strange for humans or fusion to be seen as negative. She got offended when peridot called her defective because she secretly sees herself as that way.
Hm, I could see that or I could also see in the negative life lesson kind of way that you and other fans have objected to or interpreted.
I’m a pretty big proponent for episodes that allow character building moments to our core cast, and that one for me felt like a big learning moment for Amethyst. There she learned that not everything can be taken like a joke because sometimes words and jokes can hurt deep down. Feeling that pain herself she can better empathize with others and learn to be more careful with how she uses language.
I think these lessons are really great for the core younger audience to learn from, but like many story aspects of the series this too is totally up to viewer interpretation. Each view here holds equal merit, regardless of my personal preferences.