Well my subjective opinion on it is that people who act in an ill mannered way really are nothing more than deeply wounded individuals. They are weak and frail, they are insecure about their own worlds and suffer from self esteem issues. You see, when you view your self as cheap and unworthy, you become angry and you become an asshole. You lash out on people, nothing makes you happy… and well if you’re hurting, you might as well hurt others to make them feel what you feel.. I think really its all for attention… and another reason could be jealousy… if you’re nice to somebody, even after they insult and disrespect you… if you try and communicate with them on a mature level and they still act like infants…. You put them in an awkward position because they’re used to the attention and the “fuck you back” not the wise and mature line of speech… so basically… they get angrier , more frustrated.. and more disrespectful because they know of no other way of keeping their guard up… healing, even if temporarily, their insecurities. They really wanna be more like you, more patient.. kinder… accepting of others… self sustained… self loving… instead of impatient, angry, frustrated , self loathing , envious.. etc.. but haters can hate all they want, and some times they win… but when you go back home to your loving family, and happily lead your successful life… they are the ones with nothing to live for.. feeling like an empty shell… which exacerbates their negative attitude even further.