I can think of four possible explanations for this almost unprecedented presidential detachment from the decision-making of policies the president publicly declared to be vital to the country and his presidency:
(1) He is a very, very big picture man and he delegates decisions even on the central points of vital issues.
(2) For tactical reasons, he has decided these matters were not worth using up political chits.
(3) He is either hesitant or unskilled at management and let matters drift until it seemed too late to personally intervene.
(4) Or his personality type leaves him surprisingly uninterested in things that aren’t personally about him.