Everyone comes in this world to complete his some responsesibilities so every one has a aim,every one is here for learning and teaching. A man, if you are seeing him as a ruined person,drinker,unsuccessful ya, ye you are right but this is giving you a message that if you willl do such deeds,you will be like me.
So, this person is too useful for you,for your success.So don't ignor anyone and please don't get igo in yourself,because everyone is special for God,

"God loves everyone more than seventy mothers."