Having listened to many hours of planning and philosophizing on the SO podcast as the site developed, I think the OP misunderstands their approach.
1) They are "anti-community" only in the sense that they don't want content unrelated to the site's topic. They do have moderation, votes for moderators, etc. Everything about the site is geared around getting the best answers and making those searchable, not socializing.
2) This is a tradeoff: too narrow and you won't get enough momentum to keep going; too broad and it's uninteresting. Specificity keeps real experts interested; if you know and love Unix, you'll be much more likely to hang out and answer questions on a Unix site than on a General Computer Stuff site. The whole model depends on keeping experts involved, and if a site is TOO specific to generate enough interest, they kill it. One downside is the inevitable overlap between topics. But I think it's an OK tradeoff.
3) I don't see anything like what he describes. I've been using SO since it was in beta, and I'm still getting good answers to my questions quickly. If there is a rise in militant purists, it's in response to the inevitable influx of newbies and crappy questions, which will happen to any site that gets popular. SO has had this in mind from day 1 and they actively promote community moderation, which is the only scalable approach.
I don't mean to sound like an SO apologist, but this post sounds a little too "those guys don't know what they're doing". That's the most common refrain on the internet.
The proper response, snarky as it sounds, is "you try doing it better." And it's serious. If you can make a site and cultivate a community better than StackOverflow, I'll be there.