1. Exceptional programmers write neat, maintainable code. Anyone can ship something that works right now but has maintenance costs up the wazoo later.
2. If you recruit based on open source contributions you'll miss out on the many, many fantastic devs who have no involvement in FOSS in their day jobs and like to switch off at night. (I love FOSS but I also love sleep)
3. All of what is written about in this blog entry is better termed experience. What you want is experience of working well in the industry. The blog entry is about as useful as saying "if you want a good employee then choose someone that's already shown they can do what you're asking". This is not new information.