In Starship Troopers (1997) the cast agreed to do the co-ed shower scene only if the

For people that don't read the book, the book has been accused of being pro-nationalism and pro-war, whereas the movie is satirical in nature

The books has almost the exact opposite message as the movie. I don't know if Heinlein was a crazy nationalist, but he sure wrote the book like one.

The book was satire, too

It is, just a lot of people didn't come to that same conclusion