It's not like that now. The elves have left middle earth.
HN's greatest contributors of the past, have been gone for years. Worse still, the site's audience has broadened greatly and its content has shifted towards the very mainstream news topics that it once avoided. Moderators have clear political axes to grind. While the site initially shunned submissions related to politics (and even codified this in its guidelines), it's no longer uncommon for flags to be turned off explicitly political stories that lead to viscous flame wars.
HN is invaluable, as a reminder in the fragility of communities and of the impermanence of anything we create. If a project that some of the smartest people on the planet put their heart and soul into can fall apart so ruinously, who are we to have any ego about our creations?
If the question is "what site in early 2018 most resembles HN of 2006", I believe the answer is Indie Hackers. Its community is open, friendly, genuinely helpful and focused on business.
It's not quite the same since it takes more of a pro-bootstrapper stance, but then again the HN ethos used to be more tilted towards frugality and truly early-stage companies than it now is.
Things will undoubtedly change as they grow, but IH is arguably the finest place on the internet for entrepreneurs.