Being right isn't enough to be interesting. The key thing is the amount of information in the message. High-indignation, low-information messages produce uninteresting discussion on HN.
Actually Theo's message may not be so low-information in its original context, where there's a lot of shared state i.e. implicit information. But that doesn't carry over automatically. Posting a mailing list thread to HN is a lossy operation that way.
