I don't question your ability to call for it, but I don't think it's realistic to expect it. HN is built on a whole lot of user participation, but YC has also spent millions of actual dollars keeping it running, maintained, and moderated. It belongs to them, not to us.
Your recourse, if you don't like how they're managing it, is to start your own site, or to move to a different site. Indeed, if value on HN primarily comes from its users, as you say, it's hard to imagine a more powerful recourse to have.
Tangentially, I think HN's value to YC is hugely overblown. YC has been privately telling batch companies not to participate here for almost the whole time the site has existed. The fundamental key to YC's success is being first to fully commit to a market for small investments in marginal startups. It was an extremely good investment thesis, and it compounds dramatically every year as the value of the alumni network increases.
YC could kill off HN tomorrow and it is unlikely it would harm their returns at all. If you're not close to SFBA tech company investing it's easy to miss the extent to which YC is currently running the table on small startup investing, and none of that has anything to do with how HN is moderated.