I don't want to argue that graph theory is more important (though I could list which topics I think it's more important than). Rather I want to argue that, part

I don't want to argue that graph theory is more important (though I could list which topics I think it's more important than). Rather I want to argue that, partially because primary and secondary school educators don't have so many years of preconceptions about the right way to teach the subject, it can do a better job building the underlying skills we want to teach students in teaching them math. We don't teach math because we want students to know facts (the correct answer to "What's the derivative of arccsc(x^2)?" is almost always "who cares?"). I certainly don't think that basic graph theory should be reserved for "advanced students." This second grade experiment shows that it's accessible to everyone.