Summarizing his statement wouldn’t do it justice so I recommend you read it in full, he explains why he does it and what has DC done to anger him to this extent - but it’s also a move about more than just to spite DC.
original source (Willingham’s blog): https://billwillingham.substack.com/p/willingham-sends-fables-into-the
This is just so sad and really make me second guess buying ANY DC comics. I loved these books and thankfully I purchased them back when they seem to have been honoring their contract with him.
My kiddo will be reading pirated copies, and hopefully I can find a way to send him the cut he’s owed.