Did you not look at any of the criticisms included on the wikipedia page? "Debunked" may have been overly strong, but it certainly lacks evidence and there are some good arguments against it.
I'd say "debunked" is putting it mildly. "Vacuous nonsense fuelled entirely by cherry picking and special pleading" is the phrase I'd use. See for example his response to the Epic of Gilgamesh.
[1] https://en.wikipedia.org/wiki/Bicameralism_(psychology)#Issu...