I don't want to take sides between two good friends, but I do have strong feelings on this subject.
HistoryLink is a valuable adjunct to Geni projects. We need more and better publicity for both. Links in the projects are an easy way to do that.
One thing about Geni is that the learning curve is scattered. There's no straight line for understanding what to do and how to do it. That means users won't know the value of adding profiles to projects unless they see it explained somewhere. And, one of the main benefits to users of adding profiles to projects is that they can get a project report for their ancestors at HistoryLink.
As I talk to users, I often find that people think projects (and HistoryLink) are for curators only. I see a general lack of interest until people understand that they can participate. If there's any doubt about this, notice Dimitri's comments above. Even a curator thought there was a time when projects were curators only.
Projects and HistoryLink will never reach their full potential if curators plan to do most of the work themselves. We need much more user involvement.
For me that means that EVERY PROJECT in HistoryLink should have a link and a very short explanation of what it is. I've been adding text at the beginning of project pages that says (for example), "Add professional cabinetmakers and furniture makers to this project. You can visit HistoryLink [link] to find out which projects include your ancestors."
Of course, there might be a better way to do it. I'd love to be talking about that.