As for the 'Build Thread Contributor' badge it is really a convenience for others. If you have a build thread and you link it to get the 'badge' then any time you ask a question or post a response, someone can quickly find your build thread to learn more about your system set up. That might provide context, provide deeper insight into your build philosophies or help someone else that is struggling with a certain concept or methodology. It also might provide some help to people considering the purchase of a piece of equipment that you are using. In short it is not a 'badge' so much as a simple and convenient way to share your knowledge and experiences with the community.