All of my blog posts have buttons for Digg, Reddit, Delicious, Facebook and StumbleUpon, none of which I use. There are a thousand other buttons I could add too. Hell, I have Adsense banners which I almost never see on account of Adblock.

It's not hypocrisy, it's compatibility. Every social networking site offers a bunch of new interactions, and you can support members without endorsing membership.

If he'd written that Facebook was evil and the following are reasons no one should use it, I'd see your point. The closest he got to that it seems to me was pointing out the quantity/quality tradeoff.

What he wrote were observations after quitting and several of the points he acknowledged were related to higher volume -- points that might not apply to readers with lower public profiles.

Actually, there was a GTD aspect of it (inbox, Tweet usage, LinkedIn) that seemed right at home for HN.

I think that actually presents a crux to his argument. I don't personally use Facebook all that much now, but I have certain circles of friends who are easily more reachable via Facebook than say e-mail or phone. While they may not be my main groups of friends I still consider them part of my social circles and would like interaction from time to time.