Correct; as with any other issue, it is near impossible to generalize among all the Protestants
Which why the Bishop of Rome, now, and in his former life as Joseph Cardinal Ratizinger has been very careful and deliberate to speak and write of "Lutherans and Protestants"--recognizing that there are many significant distinctions.
For another: The Lutheran Confessions (Formula of Concord) explicitly name Mary as mother of God.
You are correct; indeed continuing Lutherans are in the league of their own and should not be swept up with the rest of the Protestants, especially their more recent versions and after the Joint Declaration of Faith cleared some old misunderstandings up. I apologize for being too polemical and imprecise.