Because in the middle of the first half, where Morton's a fish out of water but not having that experience (he's being treated as a human in need, not
a marooned space alien), Sayles reveals Morton's on the run.
Attacked by a mysterious swarm of mechanical
space bees, the crew becomes
marooned separately, the better to give each member their own special screen time, Kirk engaging in his patented brands of derring - do with an adoring Chekov (Anton Yelchin) by his side, Spock and McCoy bonding in their uniquely prickly way as they argue over emotion versus logic, and Scotty (Pegg) confronted with a plucky
alien woman (Sofia Boutella, triumphing over the stylized makeup and pert ponytail) who is just as mechanically inclined as he is.