While I do realize how important people like sanitation workers, etc. are, I am not sure if I could ever be a person who just blindly fulfills the needs of a society. That is why I myself have a fear of having a low IQ, because it means that it would be unlikely that I would be successful in the career I myself want to pursue (biophysics).
While determination is important, determination in and of itself isn't going to make you successful if there is something else making what you want to pursue either extremely unlikely, or outright impossible. I am also not a huge fan of labeling kids "gifted" and such. I was in a "gifted" program for all of elementary school, and I feel like telling kids that makes them less likely to put in the effort they need to succeed.