I see, you certainly seem to be being intentionally obtuse. For the record I was just letting you know why you’re being downvoted. But that’s some pretty big projection there with the “looking for somebody to be mad at”. You’ve clearly got something stuck in your craw about this and I have no idea what it is.
At the end of the day even the Supreme Court couldn’t come up with this one with the chief justice at the time saying “I don’t know how to define porn but I know what it is when I see it”. Those things that we can agree on are law, and we’re still arguing about the ones we can’t hence this article.
But your original question was why doesn’t somebody just decide what’s bad for society? And the answer is because censorship is bad, whether you like that answer or not. To paraphrase a famous quote, “the road to hell is paved with good intentions”.