From what I remember this guy had a different name, and was in prison for rape, when he made up this holiday. He did it because he hated what he considered was the "white" American Christmas celebration. Later he changed his name to Karenga. Where the idea of him being a professor came from, I can only imagine...probably from the mind of some liberal journalist who wanted to spread a lie. Of course, when Kawanza gained some popularity, the media never mentioned that it had been thought up by a jailbird - as a protest against Christmas.
And who ever heard of a celebration of the harvest...in any country...in the winter? The whole thing is a joke, including the stolen idea of lighting candles like during the Jewish celebration of Hanukkah.