Great comment about font design in general, although in this particular article it seems like it's not fallacious at all. They seem like they're explicitly going for a handwritten effect, and are willing to sacrifice legibility to get it. The images at the bottom of the page achieve a hand-made look, and having the letters look like they were drawn with a brush or pen -- including all the flaws that come with that -- is part of the (quite impressive, IMO) effect.