Please don't misconstrue this as a form of elitism. Rather it's a matter of expectations. I've been a member of Reddit (under different nicknames) since their early days, and still have a somewhat active account there.
Currently when I visit Reddit I expect a good laugh, some cute pictures, conspiracy theories, sensationalized headlines and the occasional good article and/or discussion. When I comment on Reddit I do so at my own peril, knowing all too well that it's acceptable in that culture to be rude and to offend other redditors, while hiding behind a monitor.
Programming.Reddit was the last subreddit where I had some sort of expectations left in regards to learning about, and commenting on, interesting subjects with other professionals. Sadly the mob culture has reached that subreddit too. Anything Ruby or Rails related is considered fair game, and if you hang out there, you'll see a lot of unjustified bashing and character assassinations. There are still good discussions, articles, and good people (like dons), but overall I've lowered my expectations of what I can get from, and offer to, that community. The "alanic" thing is that Python receives a lot of attention and respect in that community, and yet Python and Ruby really are not that different. Their communities may be slightly different, but I wouldn't trust anyone who highly praises one while drastically dissing the other.
I've simultaneously had my posts on the homepage of Reddit and Hacker News, including Programming.Reddit. The difference between the two groups of discussions was huge. For example, my post about a great math book generated a series of discussions about math books in general and other reading suggestions on Hacker News. On Reddit the top comment was a link to the Pirate Bay, plus other comments that essentially said "I agree". So while it's not a problem, I have different expectations from the two.
I can go to Reddit, Digg or even 4chan for a cheap laugh. But that's not why I come to Hacker News. I come to Hacker News, increasingly more often, in the hope of learning new things, sharing ideas and having nice conversations with like-minded programmers and hackers. Polite, civilized, mostly serious conversations. Conversations that don't require you to be juvenile and rude or that always degenerate into meme/pun threads. And I also expect to network with people. Guys, I'm in Toronto, if you want meet for a coffee, I'd love to. It is not elitism if I have different expectations from two communities that act so differently.
We also need to consider the danger of gradually evolving into Reddit. In its early days Reddit was like Hacker News. It was fantastic and addictive. But a lack of moderation, an increasingly wider audience and above all a lack of respect between people in the same community, led Reddit to where it is today. Reddit went from scientific articles and interesting discussions between experts to the mob-like virtual assassination of Joe Clark. Quite frankly, I was disgusted to see a respected professional be attacked so viciously by the community. That's not a community that represents me and that's not a community I have great expectations from or hopes for. And that's part of the reason why I'm pretty much leaving Reddit behind in favor of Hacker News. It's not perfect here, but there is a much better signal to noise ratio and sense of community.
Thankfully PG has a clear idea of what this community shouldn't be and as such there are explicit guidelines (http://ycombinator.com/newsguidelines.html). Stories get flagged and killed regularly when they don't belong. This, combined with a very clear intent to keep the conversation civil ("Be civil. Don't say things you wouldn't say in a face to face conversation. When disagreeing, please reply to the argument instead of calling names.") makes Hacker News the great, unique site that it is. In all fairness, I don't feel elitist for enjoying all this and expecting nothing less from Hacker News.