One of the things I've been doing in fits and starts is discussing SF with kids, specifially why they prefer fantasy, and why they won't read it, though some do watch it on TV. (None of them like Battlestar Galactica, Firefly, etc--all too grown up, not surprising, but a bunch of them watch anime, esp. the kids who speak Asian languages as first or second language.)
Anyway, though of course my sample is small, what I'm seeing in this limited sample is that sense of wonder shapes differently for kids now than it did for us forty years ago. Just generalizing here: they don't want scientific discovery as a goal--that's too much like the slog of science class. What they really want is the impossible.
One girl said, in answer to my "Don't you like stories where the people go to interesting places?" "I don't want anywhere here. That's so boring. I want the make-up ones." and everybody chimed in, "Yeah!" Further questions clarified that class's attitude: they want other worlds, not Earth--and when one boy said, "I want dragons!" there was another spontaneous "Yeah!"
They want surprises--and they want the sfnal elements to be tools for action, not the point of the story. In other words, the scientific method, which used to be so exciting in and of itself, is no longer exciting, at least in this tiny corner of the kid reading world. They get the scientific method every day in class, which means tedious memorizing, labs (okay, fun, but not to read about), and worse, long lab reports. Google Earth shows them anywhere on the planet, which is fun, yes, but again, not to read about. "Star Wars is fun to read about," a timid little girl said at the very end of the discussion in that particular class.
A kid who lives nearby said, "People in science stories are always boring. All they talk about is the stuff they are learning." "What about cool experiments?" I asked. I got a shrug, and a perplexed look, so I added the leading question, "You want the experiments to do something, you don't want to read about them as the thing the kids are doing?" Hideous syntax, but his face cleared at once, and further clarification revealed that, yes, he understood it to mean that action rather than ideas was the lure.
They prefer fantasy because you don't get science teacher lectures, you get action--and you get dragons.