Iago's web of evil, who do I feel sorry for?

  Iago manipulates many people, he makes them do his dirty work for him. I feel sorry for some of them, but for others I don't so much. I feel sorry for Cassio, because he hasn't done anything wrong, Iago made him get drunk and made him lose his job. And Iago was the one that tricked him into talking to Desdemona to get it back. The person that I do not feel bad for is Othello himself. Even though Iago tricked him into thinking that Desdemona was cheating on him, he should have never doubted his wife's loyalty, she never gave him any reason to think so.