Even after reading and enjoying the book I still love the film but I can completely understand Weuve's hatred of it. The book is serious miltary sci fi with a serious political and philosophical message. The film is tongue in cheek cartoonish space opera. It is in fact a complete and utter travesty of the book.
Anyway the story is familiar to most about a young man growing up in a society where only those who complete a term of military service can vote. Against the wishes of his parents he joins the mobile (space) infantry and ends up in a war against a insect like alien race. Heinlein's political message however is serious one and when the protagonist's teacher uttered the most often repeated quote from the book: “Violence, naked force, has settled more issues in history than has any other factor.” Heinlein was making a direct rebuttal to those in the late 1950's who believed that the USA should back off its nuclear weapons programme. The military side of Heinlein's book is far more serious too than the comically inept tactics and weapons we see in the film with serious military tactics and weaponry being employed.
Perhaps the most striking thing about this novel for a 2012 reader is how little it has aged after more than 50 years. Heinlein' vision of troopers in power armour suits free-falling in disposable capsules out of dropships to fight battles on remote planets is still relevant. These concepts that Heinlein pioneered still crop up in literature, video games and movies.