Maybe, depends on your social circle, but the main reason I left facebook more than a decade ago was because everyone I had on facebook _didn't_ hold any discussions or post anything original. It was all just sharing random crap they liked, or reposts from Instagram. I don't care about some random blogspam article my cousin liked. I joined to find out what was happening in people's lives and none of that was on facebook, it was all on instagram or whatsapp. (So I totally see why facebook bought out those two companies)
The average HN reader passes judgement on Facebookers (myself included), meanwhile we waste time on sites we're convinced are "better"... but often it's just a tradeoff. HN: external links to thoughtful and informative articles, apolitical, but very impersonal and humorless. FB: insular, but (in theory) you know people, and maintain your relationships with people you don't see in person.
I don't mean to say "both are the same" -- that would be too facile. But, I don't think one or the other is clearly superior in any absolute sense.
Millions of people disagree, and frankly it's not our place to judge what is useful for others. It's not all snark and misinformation.
> The core difference is that while Facebook seeks to keep our eyes on facebook, places like HN actively encourage people to post links to material outside the core service.
But that's just an opinion, that staying on-site on FB is somehow bad. They would argue that they're encouraging users to hold discussions with people they know, highly social and relatively unmoderated.