I dont agree with this article. It does not take into account that there are people out there that truly understand technology.
In the article the author assumes that there are no good reasons to download apps outside of the Google Play Store which is not always the case.
This are instances where you need to download apps outside of the Google Play Store such as downloading of network penetration testing tools that typically violate the rules of Google Play. Also, if you plan to root your phone to install Cyanogenmod or other rom you will need to download outside of Google Play.
I would have expected a more informative article out of Wired Magazine. See article below.
Never Ever (Ever) Download Android Apps Outside of Google Play