PPP has to do with 2 primary criteria.
1) A project is actively protecting the profile
2) The profile needs special protection that a PPP can provide.
This generally means that the profile is in risk of the few things a PPP can provide, such as LNAB protection or Parent protection. What PPP does not provide is virtually everything else. What it will allow would be things like adding/removing spouses, adding/removing children, editing the biography, editing dates and places, and editing all other names other than LNAB.
The reality is that very few profiles need a simple protection for only the LNAB and/or parents, unless there's a significant risk that someone might attempt to change them either through editing or through a merge.