That is what annoys me about adaptations. If you're going to take the source material that changes it so much that it is unrecognisable from that source other than by name, then make something else!
I understand the need to change some things to work better on the screen but they often go way too far. For example, in Walking Dead, a lot of the things in the books were WAY more dramatic and powerful than the tv show, and could have easily been directly translated. Dale's death is just one example. It was awesome in the book, but on screen it was just wasted.