Earlier quoted context omitted.
No, he's saying the opposite. He's pointing out that most online communications channels haven't solved the problem of filtering your output to specific audiences as you deem appropriate. For any single service, you're generally either communicating one-to-one or one-to-everybody, with no options inbetween. This is a problem that is more easily managed in "real life" by the obvious limitations of presence.
And easily managed on the web by having multiple twitter accounts or email lists. I really don't see the issue, and I think that's why nobody has done anything about it.
Most sites just don't support multiple logins.