Iago is such a fascinating character who equally repells the audience but also attracts them. What is so interesting about him is the way that he, like Richard III and other Shakespearian villains manages to inspire trust and confidence in those around him in spite of his clear and obvious villainy. Perhaps the scene that inspires sympathy most in the audience is in Act I scene 1, when Iago describes how he was not selected for promotion, in spite of being favoured, an Cassio, a man who lacks the experience of Iago, was selected instead. Iago's judgement that Cassio is "mere prattle without practice" is an argument that presents his annoyance as being justified.
Perhaps the moment in the play when Iago appears most unworthy comes in Act V scene 2 when he kills his wife in front of an audience. Gratiano communicates the intense shame that his act shows when he says "Fie! Your sword upon a woman?" Certainly the way in which Iago attacks the defenceless Emilia, calling her "villainous whore" and stabbing her before fleeing earns him nothing less than the audience's complete lack of favour and disgust. This is the point when any allure Iago's character once had has now well and truly disappeared and his evil characteristics have manifested themselves well and truly.