I've never seen something like "Rand versus Gladwell" get such a rise out of anybody, ever. Hacker News has religion-v-atheism topics that manage to stay relatively calm. The fact that this is what made somebody flip out I think is a sign more of desperate blog-spam than it is of the actual Hacker News people going berserk. Luckily this was a single person.
I think, though, that in the last few weeks Hacker News has tipped a little bit: a lot of new people are joining, and as a result, the site might be at risk of becoming diluted. Hopefully that won't carry too far (I remember reading that in Usenet, every September would be difficult as new people joined, but until AOL added the feature within a month everybody would be properly inducted).