It is a controversial statement but it would make sense if he elaborated further. One of my first memorable experiences starting out at college was walking into a computer cluster and finding that every machine ran a variant of Red Hat's Linux. I was taken aback by the freedom the OS provide (the ability to customize every bit of your experience using the workstation). I was also positively taken aback by the community that had adopted this system. Right next door to the main cluster was a room occupied by a group of hackers. Their attitude was like nothing I had seen before. Their doors were always open to anyone who had questions about Linux. They wrote software to make using Linux easier at school. You get that same sense of community from Linux users on the web.

The statement doesn't just apply to software. Think about the Arduino. The project has gained a massive following and created a whole new legion of hardware hackers because it is easy to obtain (designs are open source and collaborative in nature) and there is a strong community behind it (probably as a result of it being open source).