It's all people who don't read much or only read modern stuff, heinlein was an author who explored ideas he wasn't someone who believed that his job was to tell people what to think. People who think the book is trying to be pro or anti anything are honestly borderline illiterate, they certainly haven't read his other work.

The movie is just a dumbed down action movie directed by someone who didn't really understand or enjoy the book - is a great movie for an action movie but it's not very well thought out and it's certainly not deeply thoughtful.

The film misses all key moments - the first scene, Zim throwing the knife, etc and everything subtle that really makes the story and emotion work - for the film the ending makes no sense, in the book it's really powerful.

The movie isn't really about much, the book is about everything - along side Friday and Stranger it's a fascinating insight into the evolution of Americanism and cultural ideals pushed to absurdity. That's not to say it should be read expecting answers, prime golden era sci-fi wasn't about giving answers it's about posing questions - hence foundation, the laws of robotics series, Stainless steel rat, etc - 'We must be as stealthy as rats in the wainscoting of their society' it's not about telling you how to live or how not to live it's about showing possibilities you probably haven't thought to explore.