To explain how we as people let this go on is difficult. There are not many choices and either you put it aside and get up and carry on, or you succumb. A vast majority of us put it aside. I just blocked it from conscious memory until many years later. As I began to remember myself, my toddler was talking about some very "strange" things and the full horror of what they are capable of sank in. They were after my first born. Moving away was not enough, I had to stop all contact with my family and the town itself.
My life looks like so many other lives. I have a college education. I grew up going to church on Sunday and having neighborhood barb-b-ques in the backyard. They hide in plain sight and have infiltrated every nuance of what we would call "normal". What is "common sense" really? It is the belief that is "common". What is common is what we've been taught to believe. Most of it is fiction.
This video is long and will challenge much of what you assume was "common knowledge". I offer it here as food for thought.