Why not show our identity? It might let people know about the site and help to grow it. webdesignernews.com and producthunt.com do this, and when I see incoming

Why not show our identity? It might let people know about the site and help to grow it. webdesignernews.com and producthunt.com do this, and when I see incoming ref links, I always feel thankful towards them. What is the negative effect?