They have so far and have reason to continue to, not just because of how they feel about HN but because the economics of curiosity are a good fit for YC's business. That's the miracle (I would even say) about HN - it occupies a sweet spot where it can be funded to just be good*, and the economics work because it's in the interests of the business.

I've written about this a fair bit over the years if anyone wants more: https://hn.algolia.com/?dateRange=all&page=0&prefix=false&so...

* ("good" macroexpands to "as good as possible under the circumstances")