The shock and the horror of this idea must've been the most terrible thing in the world and then the question comes: do you follow orders and burn what you've defended, or do you let it be?
As valet, he kept Gerald's bedroom in order, and, as butler, he served the meals with dignity and style, but otherwise he pretty well let matters follow their own course.
Harry could hardly believe that Dumbledore would not have intervened if such cruelty was happening inside his own house, and yet there was undoubtedly something odd about the story.
If you just let everything slide, if nothing gets challenged, if you don't try to really pin down what somebody's saying, you get a very lazy form of thought.
One of the most basic delusions of our time is that home life takes care of itself naturally and that the best strategy for dealing with it is to relax and let it take its course.