I think Pohzee's point was that it wasn't a totally stand-alone story.(like Watchmen) It was built on all the work that had been done building up the JLI. This series can't be told without knowledge of the work that came before. Personally I don't have an issue with that, but I also understand that it's too bad King isn't interested in adding to the collective lore. As you said, this story isn't meant to have a follow-up, which isn't usually the point of writing a story using these shared characters, where one writer after another contributes their stories to the larger mythos.