“If Othello really is that decent, honest, and credulous, if he can really have friends and be loved by a beautiful woman, the white characters in the play can’t accept it,” Spiro said. “Iago has to destroy him.”
http://www.slate.com/articles/arts/theater/2015/11/why_is_othello_black_understanding_why_shakespeare_made_his_hero_a_moor.single.html