It's probably a combo of the fact that he's YC alum, his articles are also an experiment in art directing every single individual post, plus you don't find a lot of designers that exhibit the hacker mentality of tinkering with stuff in public to see how it works. As a designer, the natural instinct is to wait until something is fully baked and say "ta da! look how pretty this is!" rather than show a work in progress.

That's what makes Mark Boulton's Drupal work so interesting as well:

http://www.d7ux.org/