Some are less social than other’s there is no blanket making all friendly, respectful, kind, caring individuals, among us “humans” and some mad dog monsters capable or even with a proclivity toward cruelty.
Some people are just not as nice as others even if you don’t do or say anything that might illicit that nastiness.
The Dali Lama (head of the Tibetan Buddhist monks), says that you can be full of kindness and love but, that you cannot sleep with a mad dog.