> But is one’s life diminished by hearing bad 
    > ideas? I don’t think so

You may think that it's harmless to thousands of racist theories floating around the internet. I don't. I think it plants seeds of doubt. "Group X must have done something to make so many people hate them" etc.

Let's say I publish an article alleging you murdered your previous girlfriend/boyfriend. It goes viral. A month later, the truth airs! Someone publishes a follow-up explaining that you are innocent. Do you think your life will just go back to normal?