The Changes log gives the name of the person who locked the profile (made it a PPP) and this person posted a general explanation on their personal profile.This seems to date back from a time when the software did not force a merge to go into the profile with the lower ID, so in order to prevent merges from going left and right, and make sure they got into the lowest numbered profiles, lots of profiles were locked preventively. The criteria for locking (PPP'ing) a profile changed and became much stricter later on.
If you allow a couple of days for project leaders to chime in, then I'm sure either a project will adopt the profile and work with you, or the PPP will be removed.