I started to dislike kakashi when he started playing favors for sasuke. he didn't tried to teach naruto chidori. the fact that he gave naruto to Ebisu to train means that he didn't fully realized naruto's skills, strenght and weaknesses. I don't think he cared much when Jiraya told him he is taking naruto. the only thing he did for naruto was chakra controll, and that 1000 years of pain. he was yelling to jiraya why he thought naruto rasengan. if this doesn't say he likes sasuke more I don't know wut does. so him being a good teacher, no he fails badly.