Relatively speaking, those who are 3Qed but not offered appointments are, by definition, minimally qualified. In relation to others, their academics, extracurriculars, and leadership potential are not quite up to the standards of those who are offered appointments. Your assumptions are based on the premise that all those below the 3Qed line are offered NAPS/Foundation. This is not true. Those who are offered the prep programs are generally those with outstanding extracurriculars and/or leadership, but specific glaring academic defencies. Once these deficiencies are rectified, these candidates become extremely competitive, perhaps even into the national pool range.