Open source hardware and the free rider dilemna

I wrote a post on my personal blog about using content from open source projects in general and the Open Energy monitor in particular. Here is an extract of it:

There are now more than 960 registered members in the community, not all of them are active and quite a few contribute actively to the development of the project. But does that mean that the others are just passive members? free riders? is that fair?
I started toying with the idea of using an arduino to monitor electricity consumption about two years ago, and I found out that someone else (Trystan and Glyn and quite a few others) already started developing that idea and sharing their work and findings online. Sharing their work and code online does not only save other people (actually humanity in general) a lot of time and effort, but it also allows for a much wider scope of fellow tinkerers to review and improve that work.