"a bit odd..."

"We may want children to learn science and languages, but our societies regard children and adults who enjoy doing that as a bit odd."

"The rhetoric in the field doesn't distinguish between 'the child reader' (roughly understood as any child given a book and told to read it) and 'the reading child' (from whose hands you have to remove the book so that they can eat.) And it doesn't distinguish between what different children read for or take into account that SF readers might have different criteria and priorites than the reader of realistic or fantasy fiction." 

--- from Farah Mendlesohn's article in the Horn Book about SF for teens, The Campaign for Shiny Futures

As a child and adult reader of SF, I have to agree. If a SF book doesn't have a cool IDEA at the heart of it, then meh, meh, meh.  You can have lovely characters, great plot, emotional turmoil, but if the idea being explored is trivial or plain stupid, then it isn't speculative fiction. The whole point is the speculation, the playing out of the "what if" in a creative way.  

Here are some books that I read quite awhile ago, and while the plots and characters may be hazy in my memory, the "what ifs" are not. I've linked to GoodReads so you can see the variety of reactions to these titles, which clearly reflect individual readers responses to the ideas in the books more than their literary merits. 

Beggars in Spain, Nancy Kress: What if certain members of the human race didn't need to sleep? And suffered no ill effects because of it? 

Native Tongue, by Suzette Haden Elgin:  What if linguists ran the world and a language exclusive to women became a secret weapon? 

Enchantress From the Stars, by Sylvia Louise Engdahl:  What if you were so culturally ahead of an alien race that they looked upon you as a magical being? What are your obligations to a "hero" who puts his faith in you? (Newbery Honor, 1971)

Bellwether and/or To Say Nothing of the Dog,  both by Connie Willis:  How does chaos theory play out in love and in real life?

I'm not saying that a great SF book can't have intriguing ideas and fully-formed characters and marvelous literary qualities. I'm saying that without the shiny idea, a SF book doesn't even get off the ground.  And in SF for teens, this so important that if the idea is shallow or missing those YA readers go elsewhere---straight to the adult shelves. Brava to Ms. Mendlesohn for saying this out loud.