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Iago is a rampant misogynist. It's possible that he is as misogynistic as he is because it has been theorized that he is actually gay and in love with Othello, which would explain why he so passionately hates Othello as no concrete reason is really given. The opposite of love isn't hate, it's indifference.
Iago finds women faithless, even suspecting his wife of having an earlier affair with Othello (It is thought abroad that ’twixt my sheets / He has done my office” (I.iii.369–370)). The only thing he seems to find women good for is to use them as pawns in his machinations, not caring if it harms a woman (such as Desdemona) in the process.