Honestly this would make a great movie - a society where being mean is outlawed.
You're making this into a slippery slope when it need not be. The parent commenter didn't say anything about mean things, they were talking about hate speech.
Examples off the top of my head: the demonization of "illegal" when in reference to people who cross the border without the right to do so.
The willful conflation of "Muslim" as a race rather than a religion.