There's but one reason why this argument is made - stupidity*. Even if MS is intelligent, he is limited in expression by the stupidity of his target audience like all creationists. Evolution removes creation from god, making it a target, and the ego of the simple minded easily rejects classification as a primate. The ol' "we don't comes from monkeys 'cause we's special" assumption.
*scientifically naïve.
*scientifically naïve.