alt Hacker NewsNot criticizing is not for hiding fact you hate someone.
Not criticizing is about - you see someone slipping don’t call them stupid just move on.
Like if someone makes a typo in comment here on HN, no one writes how stupid they are because they might be on the phone having autocorrect breaking their typing. You don’t really show off how smart you are pointing out small mistakes.
Hating someone requires that they somehow wronged you. There was nothing in the book about being nice for someone who is swearing at you or punched you in the face.
Whether someone is swearing at me or punched me in the face is not a factor. I believe the point of the book is that criticism tends to be taken personally. I'm sure you can guess what that implies.