Teachers of weed-out courses do just the opposite. They shrink from the task of being responsible educators. They build the illusion that students aren’t good enough despite their best efforts instead of taking charge as teachers. Sure, it’s easier to place the burden of understanding notoriously taxing topics on inexperienced students, antagonizing them when they don’t get it right on the first try, than it is to put in the added effort of making a difficult subject clear and manageable. But just because it’s easier doesn’t make it right.