Comment by coldpie

I guess the WWW itself is what you are asking for. You simply can't scale a single community to include all of humanity. You need some way to filter out abusers, and people will vary widely in where they want to place the line of what counts as acceptable behavior. Given that, you need some way to exclude people from spaces they aren't welcome in, and different discussion mediums in order to encourage or discourage types of behavior. This leads to different communities with different expectations of behavior, and that's exactly what we have on the WWW.

Usenet worked because it was small, a very small percentage of the planet used Usenet.