We have a large number of projects that are meant to serve as tutorials, top-level portals, or for purposes other than collecting profiles. (Often, the profiles are added to sub-projects.)
No matter how much the index says "Please do not add profiles," people still do it, which results in more work for the other collaborators who have to keep "moving" profiles to the right places.
It would help if project creators had the ability to check a box saying "Do not allow profiles to be added" at the time of creation. It could also be a feature that curators could use later on -- for example, if collaborators decide later that they want to enact a no-profiles rule, or if curators see that a project is being used for abuse.
Country portals are already set this way by Geni staff, so hopefully it's possible to extend that ability to others.