Strange that you at O'Reily don't understand it with all the IT expertise...
It takes 5 seconds and 35Kb of traffic just to download one comment. There are nearly 150 comments on this article. To look through all of them would take me 12.5 minutes just for loading. The total traffic would be more than 5Mb. At the same time, average comment is just about 500 bytes (100 words). It would probably take from 10 to 20 minutes to look through all of them and total text content is only 75Kb.
So the reader has to spend nearly half of the time waiting for the page to finish downloading and has to download 5Mb of unnecessary HTML code for only 1% of valuable content.
Amazing how you can get so many things right and still get as many of them wrong.