on one hand, Lebron is a transcendent who should be the on taking it to the rack vs doing what the other 99% of the league does, take a contested jumper to end the game.
on the other hand, Lebron is kinda aging and at the point in his career where he probably should be making the transition to be absolutely confident in his perimeter shooting... I mean when I think of Lebron taking it to the rack at end of game situations, I think Cavs v Pistons in 07 or crab dribble.... those moments were 8 years ago.... a lifetime ago in the NBA, so its a safe assumption to say his game has evolved a bit.
the cynic view, however, could simply be that he is afraid of contact and don't want to get sent to the FT line.