This was true on the Huddler platform as well. We've never hidden trader feedback from signed-out visitors. On the new platform it's now possible for Head-Fi'ers to make it harder for visitors to see their feedback, but it's still accessible same as before. As always, we encourage that private information should not be included when leaving feedback for someone.
I'm going to disagree that visitors to the site shouldn't have easy access to publicly posted content. Every single Head-Fi'er was at one point a visitor. We all somehow wound up here, often because we had a specific question or were searching for recommendations. If the information we were looking for wasn't readily available, we'd probably be less likely to stick around. I know if I go to a forum and I cannot easily locate what I'm looking for, it's not likely that I'll register and join that community. We've made it easier for Head-Fi'ers to restrict what visitors can see in their individual profiles, but public posts are open to everyone and should be easily accessible.
Head-Fi is a place where headphone lovers can come together and share our experiences. It's a place for us to connect. For some of us it even feels like an online home. Head-Fi is intended to be open and inviting to visitors and members alike. We were all non-members at one point or another and eventually found our way here. Once here, we each experienced something that lead to us joining the community. Why restrict others from the capability of having the same experience?