Being pleased with an evil is a sin in itself. Every Muslim must realize that evils are displeasing to Allah. Out of his love for Allah, a Muslim must hate everything that is displeasing to his Lord. If he does not have this feeling, it is a clear sign that there is a shortcoming in his faith. In addition, he will be held accountable for his liking a sin even if he does not witness or perform that deed. Abu Dawud recorded the following hadith,
"If a sin is committed on the earth, the one who witnessed it and hated it is like one who was not present. And the one who was not present at the sin but is pleased with it is like one who was present [and did not repel it]." [Abu Dawud]
If a person sees evil around him and does not have much feeling or hatred in his heart for it, this is a sign that his heart is diseased. But when the heart no longer cares about the evil that is around it, it is, in reality, a dead heart. In other words, if a person does not mind seeing evil and he does not hate seeing all of the acts that are displeasing to Allah around him, it means that his heart has lost all of its faith and is, for all intents and purposes, a dead or useless heart. Ibn Masood was once asked what is a dead heart and he answered, "The heart that does not recognize and like the good and that does not reject and repel the evil."
"Commentary on the Forty Hadith of al-Nawawi" - Jamaal al-Din M. Zarabozo, Vol. 2, pp., p. 1009