Pitching this stuff is hard; kids at different ages see things differently, and kids in different areas age at different speeds.
I think you've hit one of the main challenge of schools outreach on the head.
We are starting to have a "recipe" for introducing adult organisations to Wikipedia which will basically work for charities, universities, museums and the like - we would need several, for schools.
Plus our adult outreach model is based on people coming to events of their own free will, not because they've been told to! I imagine that a room full of schoolkids is a much more difficult audience than what we're used to.
I think this is part of the reason why we're focusing more on universities and GLAMs at the moment. But clearly schools need to be part of the long-term plan...
Chris