Yeah, as jefffassnacht mentioned, my intent is to use a draft field as a place to store fields that are a work in progress, or are pending a future deployment.
Real life example: I might have an upcoming code deployment that relies on specific fields. Rather than having to instruct the person performing the deployment on how to export a field group from the staging site and import it into the production one, I could instead have the requisite field groups set as drafts pending the deployment.
The developer performing the deployment could then simply set them to Published once the changes are live.
