Earlier quoted context omitted.
When I actively read them, I valued the communities of Slashdot, Fark and Metafilter just as much as I value the Reddit community. Reddit is less unique in that regard than you might think. It is absolutely more replaceable than the New York Times. It's mindboggling that I even had to type that last sentence.
Your evidence that reddit is replaceable is you've used similar sites (most of which are basically dead in the water at this point). But in the same paragraph you exempt the new york times from that same reasoning. There are several large high-quality newspapers out there competing with the new york times (washington post, wall street journal, la times, chicago tribune, etc). I love the times, but "it may be less uni…
That's the point. Internet communities come and go all the time. None of them have proven to be hard to replace. Quality news organizations don't pop up every few years.
The New York Times has competitors, but not equals. All of the papers you mentioned (except for the WSJ, which is indispensable in its niche) have a small fraction of the subscribers the New York Times does, which seems like a pretty good metric for unique value.