I'm not sure that's true. I remember when "netiquette" used to be a bigger thing than it is now. People would lurk for a while before posting to get a feel for the community. Flamewars would happen if someone top-posted instead of bottom-posting. Debate still happened, and some of them would spiral out of control, but I wasn't nearly as afraid to mention my opinion about such a wide range of topics both on the web and in real life as I am now.