When word of his Legal Reforms spread across the land, it was not just the nobles who were his vassals who had become upset by the news. In fact, pretty much the entirety of the Austrian nobility was outraged by such wild and ambitious ideas.
For starters, they were unsure if Berengar actually had the legal authority to do this; technically, Berengar was a Vassal to Count Lothar, who was, in turn, a Vassal to the Duke of Austria. As such, it was entirely unclear if he had the legal authority to do away with the Feudal system in his own territory.