Have you ever looked back through history and thought to yourself, "how could they have ever thought that was okay?" People used to dump their excrement into the street. It was once common practice to simply lobotomize people with disabilities and mental health issues. Hats used to be made with mercury. In these United States, it was once perfectly legal for white people to own black people; hell, the colonies were established through the application of brute force driven by a sincere belief that the native peoples whose land was being occupied were patently savage and subhuman. We look back on these things from our modern perspective and think, "Holy shit. What the fuck?"
I wonder sometimes what we do today that will cause people 50, 100, 150 years from now to think those thoughts. I have a few ideas, I suppose.