There was so much, so very much sf-lite about that book. Real military life is full of detail and jargon. OMW had something like two or three kinds of weapons.

There was the big sex scene near the beginning of the book, and then the characters pretty much forgot about sex.

It was intentionally written to be an intro to sf for people who don't usually read the stuff. Fortunately, even though the book was quite popular, that approach to writing science fiction hasn't caught on.