If you accept that humans are intelligent, and that they can judge that another human is intelligent by conversing with them across a text-only channel, then you run into a big problem by stating that a Turing-test-passing algorithm is unintelligent. To do so would expose the fact that your definition of "intelligence" secretly includes the class "...and is a human," which makes "intelligent machine" a contradiction of terms. It is essentially an example of the No True Scotsman fallacy, because you're revealing a new facet of your claim when faced with an apparent counterexample.
If you're defining "intelligence" to be a purely human trait, then come right out and say so, and everyone will agree that on your terms a machine cannot be intelligent. Of course, I would argue that such a definition isn't very useful, since it basically means that the adjectives "intelligent" and "humans" are synonyms.