Assuming that it can be taught. It's possible that the key components that link conscientiousness to academic success are prefrontal/ventral tegmental stuff such as different reward mechanisms (motivation, willpower) and differences in executive function (attention and inhibitory control), and we don't know to what extent teaching can modify that. Executive function, at least, seems difficult to alter via training.

Plus, we'd have to separate out the components of conscientiousness though - it's possible that conscientiousness is not entirely positive. Conscientiousness has a rather controversial relationship with fluid intelligence and creativity, (as usual, most stereotypes carry at least some distorted truth) though it's too soon to make definitive statements.

I do mostly agree with you - these are just rather important qualifiers.