Aristotle wants to tackle a broader question: is happiness something to be praised or honored?
He decides that we praise virtuous activity—like courage and justice—things that are related to good and serious things and can be compared between one person and another.
Happiness, however, is a complete good in itself and as such is divine.
And divine things, like the gods, are honored rather than praised.
After all, how stupid would it be to praise the gods, as if they could be compared in their actions to anyone else?