Good post, but as someone who dabbles in trolling as a hobby, I'd like to suggest the following: Trolls are important. Trolling, especially as seen on places like slashdot/4chan/somethingawful/etc., can oftentimes be a mechanism of critique for ideas and rhetorical styles. One of the best things about the 'net is that, frankly, none of this really matters. None of it. It's a big joke. My twitters and my wikis and my…
My bank account is just an int in a server somewhere, but that doesn't make it unimportant. Obviously my karma isn't important, but that's because it has little effect on my outside of HN. Being bits on a server somewhere doesn't make it unimportant. Similarly, when someone posted a fake obit of Steve Jobs (well before he died), it caused quite an impact despite none of it mattering.
But seriously, it is a representation of something physical. Money. Money which can in turn be used for other physical things. Reputation "karma" isn't. It /is/ meaningless in this context, because you can never log into HN again and your life will go on.
I don't think the argument was "anything digital is pointless."