"Perhaps cheaters don't have anything of value to contribute to the poly community, but the poly community may have plenty of value to contribute to their lives. Especially, as InquiringOne described, those who would like to move from deceptive-cheater statusto open-and-honest-poly status, but they are not sure how. If anyone has the resources to help them, we do."
I agree completely.
"I think the real question is: Can we help cheaters become non-cheaters, and if so, how?"
Yes, I've seen it happen here on the board! How? Not, I would say, by de-emphasizing the central importance of honesty, or by letting cheaters rationalize their behavior as a form of poly. Rather, by holding to our principles, kindly but firmly explaining why their actions are problematic, and showing by example that it's not just possible but preferable to live a life based on truth, even if it's hard.
The major players. Me, 30ish bi female. Gia, girlfriend of 4+ years. Clay, boyfriend/dom. Davis, ex/friend/"it's complicated." Eddie, roommate & fwb.
The supporting cast. Eric, Gia's husband. Bee, Gia and Eric's toddler. Dexter, Gia's lover. Helen, Eric's lover. Izzy and Nikki, Clay's partners. Liam, Eddie's husband.