What? What does someone who created something you enjoyed and then stopped creating more of that thing owe anyone? An explanation?

Fans have invested in a story. They started a book, got a second book, got a couple short stories and promises of a 3rd book. No 3rd book has arrived to complete the story.

If he had said "sorry, no book 3, it's just done now" years ago, or even now, then that changes expectations. But if he's just going to avoid it all then ya, that's kind of a bad thing to do to your fans.

He has been stringing his fans along for over a decade. It is rude and cruel. It would be like teasing a puppy with a treat but never giving it to them. For 10 years. That is what he has done. His editor disagrees with me [1] but makes an equally strong point.

[1] https://i.redd.it/4g1jexk7i9e51.jpg

I guess if grown adults are akin to puppies for you in this situation and the writer is cruel and rude for not writing another book then we see things too differently to agree in any meaningful way.