Because they don't need to go off track. If they didn't cut so much shit they would have been fine, but they cut out so much, watered down so much more, and still continue to use stuff from the books, but what they use is so arbitrarily insignificant at times compared to the stuff they make up, so I don't understand why they didn't just take the last two books, combine them, and spread them out over these two seasons. Dance came out 5 years ago, I'm pretty damn sure season 5 hadn't started development until well, well after 2011. So... I don't know. Butcher storylines, remove others, combine fragments of others, good going I guess. It's just such a bizarre thing now.