And why are the modern Anabaptists also pacifists then?
You will find that many of the modern representatives of the Anabaptists (Hutterites, Mennonites, Amish, etc.) are more TRADITIONAL based than Biblical based in their beliefs and practices. They are more concerned about carrying on a TRADITION than they are about discovering the reasons that Ancient Anabaptists were pacificist or any exegetical based interpretation of the Sermon on the Mount.