While I really enjoy reading Quora and think that it has enormous potential, this type of comment shows me why I don't think it can reach the mainstream. Simply, the community is not meant for everyone. While Twitter also has a small portion of people tweeting, Quora goes even further- towards generally discouraging people outside of a small group of technically inclined giants in the startup world. I don't know how they are going to spread that into other fields in a way that continues to interest people when so much interaction with the site is frowned upon.