I’m one of them, read it when I was 25 or older. I liked the “chosen one” rhetoric being used to exploit Ender. I liked the bleakness of it all. While it was clear what the plot twist was going to be, he didn’t know, and this hit a tragic note for me. The book conveys all sides (Ender’s, the government’s, the alien’s) letting the reader getting stuck between opposing ethics, and not solving the contraposition at any point. The acceptance of the final, horrible result just adds to the bleakness created by all the violence leading up to that point.