In Sociocracy, why do not we just let people volunteer to fill a role?

From Many Voices One Song:

The basis for the decision of who fills the role is qualification. A volunteer might not be the fit person for the job. And the best candidate might not volunteer! Filling roles on a volunteer basis will not get us reliably good results. (Willingness, of course, is one factor. If someone really does not want to fill a role, chances are they will not perform well in that role.)

Inviting volunteers can get us into a lot of difficulties because it is difficult to object if volunteering is our method of decision making. The ability to object is important for collaboration. An organization is about doing something. Whether or not someone is suitable for a role is essential for creating a good work environment.

For more information, check out our handbook Many Voices One Song section 3.6.3