Why adapt it? Because Tower Junkies have been wanting a movie for years. Why adapt it they way they did, because it was a cool idea to tell the story in a way that was new for Constant Readers and for people who have never read, or heard, of the story. I wanted nothing more than to know what happened next when I finished the series. If I wanted a copy paste of the books, I can just read it again and again, but the story doesnt change. The movies/tv series wanted to give us the final turn. Some people dont want/need closure. The characters can live on with endless possibilities that way. But hey, I want Roland to end his quest and I want him to have some sort of ending...preferably a happy/peaceful one. I think he has earned it.

I honestly dont see the validity in comparing The Dark Tower with IT. It's apples and oranges. IT was already adapted into a (cheesy) tv mini series almost 30 years ago, so it has a huge mainstream, cult like, audience and IT fits nicely into a specific, popular genre. I enjoyed the hell out of the new IT movie, but it too changed a lot from the source material and not all it was for the better in my humble opinion. But you cant fit ALL that story and ALL that character development into one movie (if we are just focusing on the kids' elements of the book).