The alternative and far more logical explanation, of course, is that you surround yourself with and network with the kind of people who read HN. I do understand the global impact of a forum such as this, and I certainly understand the ramifications of a networked society. I suggest, however, that the network in this case is far smaller than supposed.
The next example is dangerous to pull off as the topic is polarizing: there is another forum called Stormfront which is the site to be a part of if you are a white supremacist (don't Google if you're at work). There are millions of posts and, I'm sure, millions of eyeballs consuming that site. If I were to ask a supporting member of Stormfront how Stormfront affects the world, they'd probably spend hours telling me about the epic discussions and hundreds of people that they know worldwide, and give me a similar answer as you -- you don't understand the global impact of what we're doing nor the network of people that Stormfront has built.
However, you and I, rational people who think that sort of shit is outer space bananas, can quickly trivialize that community because we're detached from it. Does it matter to the (much larger) community of non-white-supremacists if someone has a name in that community? Not really. So it is with Hacker News; those who think the discussions here are outer space bananas don't care about Dustin Curtis, or the flavor of the week in startups. Within a community, it is easy to start thinking that community is all-consuming and, I am here to tell you, it isn't. I think being inside Hacker News distorts views on what it actually does in the world, and what its reach is.
(Stop. Before you say what you're thinking, I'm not comparing Hacker News to Stormfront beyond that they're both forums with audiences.)
Since you qualified with familiarity with Dustin Curtis:
Before some of his posts began making the front page, I had no idea who Dustin Curtis is. I still don't, really, and my gut says he's just some UI designer slash neuroscientist who got lucky with a Hacker News audience from the AA thing, and is now considered some kind of influential voice on startups and business. If I'm wrong, I'm sorry, but I dug deep in his site looking for a clue about his career or qualifications to be a pundit on modern startups and came up pretty much dry. So I hold his opinions in the same regard as most pundits, that of immediate suspicion. That isn't a reflection on him as a person, either.