Right now I'm working for a very large European web site that's entirely written in Java. We make changes all the time (e.g. we probably make at least 3 code changes to the web site per day). Doesn't need any magic PG pixie dust sprinkled on the engineers to make this happen. What we do is run all our web server/app server combinations inside Solaris zones. When we make a change we tell the production system to shutdown each zone when it's ready (finished with current requests) and load the new one.
If the article author works at one of those "average" shops, I think he has every reason to consider his experience on news.yc as a breath of fresh air and tell other people about it as an example.
Additionally, I think part of what impressed the author so much was that pg took the time to handle the request immediately. This isn't a site anyone pays to use, there's no revenue incentive, and the request was not the early stage of a riot, but they took care of it as though it was as important as a paying customer relationship, and that's not a response you expect from most web services. In fact, I think that may be what impressed the author more than just the speed of the fix.
I am at one of those "average" shops, as are most people (by definition, although maybe not in the HN community). I know this stuff is possible but we can't do it here, and neither can most sites.
To put it in perspective, if you found a bug in your bank's website and told them about it, how long would it take for them to fix it? Even worse, what if you suggested a way to make the site work better? Would anyone with decision making power ever even see the suggestion? Just try telling someone WHO'S NOT A GEEK this story and see what they say. I wrote the article because when I told my wife what happened, her jaw hit the floor.
To put it in perspective, this is a very simple, small application with a relative handful of users that ... publishes links.
1) "capital A" Agile (even though it wasn't really about that)
2) reference Paul Graham (always a lightning rod :)
3) Ask a challenge question "Are you this [positive adjective]?"