Well, since you gave no examples or titles of the other stories, I'll just briefly explain why ASOT is a work of science fiction.
Firstly, this story takes place in the future. Which isn't a lock-in for putting it in the genre, but it's a step in the right direction. Secondly, and most importantly, it contains technology that seemed impossible for it's time. Finally, it contains a unique and changed social and political climate, which is the final nail in the coffin which lines this story up perfectly with the dictionary definition of "science fiction".