Agreed. The author: a hodgepodge of sites focused on photography, mathematics, Apple, video games, board games, role-playing games, and science fiction. Interesting? Sure. Important? Hell, no.
All these "other" SE sites are built around the things that real people are passionate about. That stuff is quite important!
Also, the attack on the "other" SE sites is lame. I regularly visit and am active on the Physics SE, and Quora's got nothing on it.