The original purpose of PR was to accept patches from outsiders (people without write access to the project repository), as an alternative to sending patches to

The original purpose of PR was to accept patches from outsiders (people without write access to the project repository), as an alternative to sending patches to the project mailing list. In open-source development if there is a core team with write access to the project repository, i would be surprised if all patches from members of the core team were merged through PR process.