It's difficult to identify any specific point in the play where Iago would genuinely command the sympathy of a reader or audience. His deepest motivations are never really revealed—at least, not in any form most human beings would understand as accounting for the degree of enmity he shows to Othello. But perhaps this mystery is the very thing that prevents some from seeing him as a "conventional" villain. In I, 1, Iago tells Roderigo, "I am not what I am." The whole speech leading up to this has a kind of pathetic quality, and as with all Shakespeare's major characters, the wording is so eloquent that in spite of the reprehensible things he is saying, the audience is lulled into thinking he's making a kind of sense. The one other place in the play where this impression occurs forcefully is at the end. In V, 2, when confronted with the consequences of his deception, Iago calmly says,
Demand me nothing. What you know, you know.
From this time forth I never will speak word.
This silence clinches the ongoing mystery, the blank at the center of Iago's soul. We are left to wonder if this man is human at all—he seems like an automaton that carries out its actions without rational (or even irrational) motivation. And yet, virtually every other appearance he makes shows the unremitting hatred in his behavior, including the vicious racist attitude he expresses against Othello. On balance, there is much more shown to us as unworthy and negative about Iago than sympathetic in any way.