EDIT: One solution would be to use a link to a webcache, or screenshot, waybackmachine, or similar
So maybe it's OK to require a proxy from China? But what if a user in North Korea can't access a proxy? Should that link also be prohibited on HN? How is HN supposed to know what consists of an acceptable workaround, and what does not? Are the standards different for different countries?
It seems simpler to assume that the articles that get upvotes have people who want to read them, and that if people want to read the article everyone is raving about, they will find a way. It's Hacker News after all.