yeah the reason for this is that It doesn't make the Science Fiction the focus. It uses it as a backdrop. Yes it goes into detail about some of it but it isn't the main focus. The main focus are the characters and the story. Because of this even when the scifi gets out of date the book will still stand up because of the story involved in it.
Also if you liked Enders Game you really should check out some of the other books by Orson Scott Card. he is by far my favorite Autor (Followed Shortly by Neil Gaimon, and G.R.R. Martin.) The Seventh Son series was great and Homecoming series were fantastic. Oh and if you like Scifi set in a modern age check out Empire and the sequal Hidden Empire. Both books were really great. Really I have not read anything by Orson Scott Card that I did not like. They are all well written and have a great story to them.