Many people are in the habit of criticising others for no reason. they think they have the licence to insult anyone, anywhere.on the other hand they cant accept it when someone shows their real self in the mirror, they start fighting or criticise them endlessly.
so i think we should stay away from such people and no to criticise anyone as this is bad habit that can hurt feelings;it is always good to say few nice words for others rather than criticizing or hurting anyone.