system
Given the following post, respond as if you're commenting on Reddit:
human
[Dune] Why was Baron Vladimir Harkonnen so blind as to the true nature of the Fremen?

Baron Harkonnen was, in nearly every respect, a cunning and dangerous man. His defeat of Duke Leto Atreides was a masterful series of maneuvers, he frequently anticipated and thwarted attempts on his own life (including from within House Harkonnen), and he was even able to manipulate a master Mentat to his own ends. Yet in always refused to consider the Fremen anything more than rabble. He refused to consider that they numbered in the millions. He refused to consider that the Harkonnen losses where the result of anything but incompetence. He refused to believe them a match for the Imperial Sardukar, despite the Sardukar themselves considering the Fremen a threat. Even when Thufir Hawat, one of the greatest Mentats to ever live, explained their abilities and their danger, the Baron *still* thought of them as rabble (even though he followed Hawat's advice towards how to recruit and train them). What led to the Baron having such a huge blind spot?
gpt
He's a racist. In his mind: Harkonnen > noble Houses > natives. He is born and raised as a noble, so he's trained to anticipate subtle political maneuvers. However, if we look towards Giedi Prime, we see an oppressed population which speaks of his very low opinion on the worth of the common people. Even after moving to Arrakis, his lifetime of oppressing the natives biased his viewpoints that the natives could not possibly be any sort of threat that his House soldiers could not handle. 

Consider the fact: he knew Duke Leto made overtures to the Fremen, at the advice of Thufir Hawat. Baron Vladimir however, allied himself to the Imperial Sardaukars, and nearly decimated House Atreides in return. After this master stroke, how could he have seen the value in anything Thufir had to say about the Fremen when he had Sardaukar under his command?