Okay, here's a "point."
What do you get when you ignore everything not found in the Bible? Fundamentalism. Christian Fundamentalism, to be exact.
Why, who are they? Presbyterians, Baptists, etc... Protestants all.
So you see, this one "point" in the article is flatly false.
Further, to compare Islamic Fundamentalism to Christian Fundamentalism is simply insane. We don't even worship the same God.
I agree that the "god" of Islam is not the Judeo-Christian God. Islam was a syncretist heresy, and its opportunistic founder took some bits from all of the religions circulating in his environment: Judaism, Christianity (but one beset by various heresies such as Arianism and Nestorianism) and paganism.
I don't think Luther was aiming for the Islamic concept of God and I don't think he was attracted by it. However, because Islam is a syncretist religion, based to some extent on earlier Christian heresies along with other beliefs, I think some of the Christian heretical elements of it may appear in Luther's teachings. They would be explicable the way the beliefs of everybody from the Docetists to the Cathars to the Jansenists are explicable, as vast oversimplifications and selective readings of certain doctrines.
What I am trying to say is that the novelty with Luther was the obsession on sacred writ as the sole source of understanding. I don't think anybody before him had done that. Of course, Luther came along after the development of printing, so probably it would not have even been possible for anybody before him to have come up with this.