You don't understand why they would doubt that the Iliad and Odyssey are entirely the work of a single person, or you don't understand how they dare, even in the absence of any evidence, to doubt the authority of the mighty Herodotus regarding a person who supposedly lived 400 years previously and about whom Herodotus had no information other than oral tradition?

I'm no sadder to assume he was wrong than to assume he was right, certainly.