> He had the presumption to fill in what the Bible leaves out.
Does that sound Protestant to you? Protestants were against things like Miracle plays.
> Dante also has a surprisingly global outlook, one quite fair to non-Christians. He heaps praise on the Saracen general Saladin, who he imagines merely occupying a place in Limbo, the place where the Just live who did not have faith in Christ in their lifetimes.
Limbo was a Catholic idea that protestants abhorred. Protestants believed in faith alone, without works (how much of Dante does this make hash of?). I don't think the person who wrote this knew anything about Protestantism, they just had some vague ideas equating it with "individualism," "progress (and by extensions reason)," and criticizing the Church, and anything that they perceived as fitting those very broad and hazy categorizations, no matter how quintessentially medieval it was or quintessentially Catholic it was, gets labeled as a cause of the reformation and/or secular humanism.
> What do you object to specifically? Dante was certainly influenced by Aristotlean thought via Aquinas. And Protestantism put individual faith at the forefront.
Protestant ideas of faith are not based on Aristotelian reason. You don't believe me? Then let's ask Martin Luther.
the Holy Scriptures and the Christian faith are little taught, and the blind, heathen master Aristotle rules alone, even more than Christ. In this regard my advice would be that Aristotle's Physics, Metaphysics, On the Soul, Ethics, which have hitherto been thought his best books, should be altogether discarded, together with all the rest of his books which boast of treating the things of nature, although nothing can be learned from the either of the things of nature or the things of the Spirit. Moreover no one has so far understood his meaning, and many souls have been burdened with profitless labor and study, at the cost of much precious time. I venture to say that any potter has more knowledge of nature than is written in these books. It grieves me to the heart that this damned, conceited, rascally heathen has with his false words deluded and made fools of so many of the best Christians. God has sent him as a plague upon us for our sins.
And you bring up Aquinas, but it's telling that the article didn't, because he exemplifies many of the trends that they're citing in Dante so by their warped reasoning he was a proto-Protestant and proto-secular humanist too (not that you can't find protestants that will agree with the second claim while virulently denying the first one), basing his philosophy on Aristotle and borrowing openly and heavily Muslims and Jews. I guess you can chart the path back, through the nominalists and volitionist scholastics that can more reasonably be cited for their contributions to the development of Protestantism, to 13th century Aristotelian like Aquinas and Albert the Great, but there were other late scholastics that stayed closer to Aristotle and Thomas. Thomas Cajetan would be a good example, since he was one of Luther's most important opponents and one of the most important commentators on Aquinas. In reality invoking Dante's Aristotelianism/Thomism really places him in the camp with the reformations Catholic opponents.
Also, I don't know anything about the course of Dante's intellectual development but the influence of Aristotle on his thought doesn't seem to have come only "via Aquinas." I think there's supposed to be a stronger Averroest influence on Dante that he'd have gotten through Aquinas. And in Paradiso Aquinas introduces him to Siger of Brabant, an Averroist professor that had been his intellectual adversary in life. I'd also assume that he read Aristotle directly.