Live interaction is great, and we will always enjoy it, but it doesn't scale: you can't go to the pub with more than a handful of friends at a time. If you take a group of fifty people out to the pub you will obviously have to break into a bunch of little sub-groups. If your two best friends end up in different sub-groups, you will either have to ignore one of them or pursue the "mingling" strategy: talk to one small group for half an hour or so, then stroll away on the pretext of getting another beer and wander into another small group.
The "live interaction" version of your Facebook page is your wedding reception. Now, I enjoyed my own wedding reception, but I also have to say that I wouldn't be anxious to hold another one. The good news is that I got to see many of my relatives, my high school friends, my college friends, my grad school friends, my music-playing friends, and my wife's relatives and friends. The bad news is that I talked to each of them for exactly two minutes before moving on to the next. Since I was the guest of honor, I was socially obligated to mingle rather than stick with a single small group, so I ended up exhausted and vaguely unsatisfied.
The "live interaction" version of news.yc is a technical conference with several hundred attendees. The good news about a conference is that nobody is obligated to try and talk to every attendee, so you are free to break up into managable little groups. The bad news is that if you're eating lunch with your colleagues in one room while DHH, PG, RMS, Woz, Bill Gates, and Al Gore are engaged in a passionate technical conversation in another room, you may never realize what you were missing. Even if you spot the PG table, you may find it rude to simply abandon your colleagues mid-lunch in order to go over and kibitz. And there are both physical and social limits to how many people can listen over PG's shoulder.
And nobody ever does that with the Web. What people actually do is create modes of interaction that are deliberately different from and better than real life. Just because you or I can't think of a mode that's as "rich" as face-to-face interaction, but is better for whatever purpose, doesn't mean it doesn't exist.
Also, going to bars isn't just about singles. Getting a drink at a pub with friends is lovely.
To a certain extend, I agree with the guy, from the first few paragraphs at least.
There needs to be richer interaction online for most people to "get it". Two-way streaming video and audio would be a start. Expressive physical avatars would be fun too.