What is Morocco's rationale for choosing the gold casket?

Morocco choose the gold casket because of how he interprets the inscription inside it. The inscription says:

Who chooseth me, shall gain what many men desire.

Morocco believes this means that in picking the gold casket, he will gain Portia, because he believes she is desirable to many men. It's hard to fault him for this interpretation, as it seems to pay a compliment to Portia. The prince of Morocco states:

All the world desires her

He also calls her a "mortal breathing saint."
However, the Prince does not know her well. He may be in love with the idea of being in love with her, but he has no real basis on which to make this claim. Further, if he wants her just because he thinks she is desirable to other men, he is using her as trophy, a way to triumph over his male peers. This is not the correct answer, and Morocco does not win her hand.
Portia, in general, objects to having no say in choosing her mate. She doesn't like the idea of having to defer to the caskets.