The problem with having recruits barely passing the minimum standards upon entering military boot camps or services academies is the unneeded stress on the joints of out of shape people, unneeded mental stress of constantly receiving extra attention for being below average, and the unneeded loss of focus the new recruits have when actually learning their military jobs. 

Being out of shape is a huge distraction for our recruits and soldiers.  Many of the active duty and reverse soldiers do not make advancement to higher ranks, therefore losing extra pay, benefits, future selection to jobs needed for career advancement.  And, on a far worse level, if the overweight and obesity of our troops is not fixed, we are dealing with a national strategic problem making it difficult to defend America from our enemies.