Engaging these racists is not a road to success and peace. Balotelli should be a cautionary tale of how not to handle it. The best thing Kean could do was celebrate a great moment with his teammates, who tried to be close to him during the boos, the chants, and that body check.
He is a kid and he is dealing with a brainless cloud of racists. It happens, it's no problem. It just shouldn't be a regular fixture in his career. The advice from Bonucci is good, just worded poorly on the blame.