The HN system works better than any other I have seen (it's kept me in line whenever I was tempted into adding noise rather than value).

I don't think degradation of HN over time is unavoidable, clearly a lot of smart people here put energy into resisting this force of nature.

One challenge is how to preserve the HN code of conduct. I've noticed some misunderstand the voting system as an agree/disagree button. I think the software should notice patterns that don't look right, such as both up- and downvotes on the same comment (popularity contest alert).

Good people + good tools = good HN.