Git-enforcer seems like it addresses a need, but I can't really see a use case for this.

For any creator/organization willing to enable this, stale pull requests will have a good reason. eg it was started by a person who is no longer actively working on the project. Having a few stale PRs isn't a big deal.

Is there a specific reason this was created? Git-enforcer has only 12 total (closed) PRs and the default max open PRs is 10.