First, they made a big mistake trying to cram way too much lore into 1 1/2 hours :P . Then, the second FUBAR, was leaving out the rest of the Ka-Tet.... it really needed Susannah, Eddie and Oy (the last 2 for some comic relief). But they couldn't have Susannah (Detta) and have Elba as Roland... this just wouldn't have made sense, given her hatred of white people, and the antagonistic relationship between her and Roland. And Finally, they could have followed, at least, ONE of the actual plot points of the books... this movies had NOTHING in common with the books, except a few character names, and Elba had a Roland-like attitude. Everything else was so far removed from the books, that it was an ENTIRELY different story... not even the mechanics of the Dark Tower were right!!!