I've seen these sorts of reactions over and over my whole life, regarding any and every book adaptation to the screen (large or small).
The basic issues, the constants, which no showrunners can overcome, are:
1) Fans of books aren't going to be satisfied with screen adaptations.
2) Fans of a TV series don't want the series to end, thus any ending is unsatisfying.
Heck, Ben Hur has had dozens of stage productions, theatrical films, and made-for-television adaptations, and you know what? None of them follow the book! The book has it all, including a made-for-Hollywood love triangle which is oddly absent from the adaptations. Believe it or not, a Christian ex-General wrote in a love triangle that salacious Hollywood left out.
And don't get me started on Master And Commander! Can you imagine the entire Fire And Ice book series, or the Harry Potter book series, or the Lord Of The Rings book series being crammed into a single film? That's nothing! Master And Commander crammed a brilliant 20-novel series into a single film! Or entirely failed to cram, actually, the film having almost no resemblance.