Outrage du jour?
Debating whether free speech should be upheld, and to what degree, on the biggest online forum that exists, is a pretty interesting topic to me and many others who upvoted the article. And I do think building a successful social network ought to be of interest to HN. While the topic may not satisfy everyone, it's a single extra headline on a page with 20 others and is easily ignored. Right now there is NOTHING about reddit on the front of HN, which is pretty odd given its origin as a YC project and the number of people interested in recent news about reddit.
This is exactly why I don't participate on HN often. If the mods want everyone to hold the same opinion, great, but don't expect much real growth or interesting discussion from that policy. Shutting down debate is childish