I just read the book for the first time, and I have to say the adaptation (sort of retroactive lol) was pretty good for the book.
The book was brilliant though. It also includes a few treatises on why fascism is the closest thing to morality that people have.
On the one hand, the arguments are absolutely gorgeous and it'd be good to get them in the political discourse. Honestly, great exciting stuff. On the other hand, they were good arguments and you could read that book as a manual.
In the end, whoever suggested this book for this movie really did something remarkable.