“roadblock” !?
reward (and punishment) has been a mainstay in the system of Chinuch that the Jewish People have used since their beginning. it is the primary system with which Hashem conducts the world.
is it the ideal method of Chinuch for the near-perfect person? no.
the desire to do Chesed, to do Hashems will is of course a nobler impetus, but its not the best or most efficient way for many children and stages of growth. of course the hope is that eventually, with proper instruction, encouragement and example we hope the ideal motivation will be achieved, but lets not throw out an extremely valuable technique.