The Poetics has a couple of big advantages over The Ethics. For one thing, it’s shorter. That’s always good with old stuff. Back in the day people weren’t really into keeping things to a reasonable length. Like Dickens. Guy wrote two good books, and they’re his too shortest. Let that be a lesson to all of you.
At any rate, the other advantage is that the assertions aren’t as ontologically grounded. While both books are all about what’s good, talking about good plays is easier to do without sounding sanctimonious. Also, The Poetics includes an intriguing look at early understanding of the parts of speech, including defining nouns and words that don’t require tenses to make sense.
So I don’t know. I’ve never been a big fan of Aristotle, and I definitely haven’t had any changes of heart here.