The purpose of content is to communicate one or more messages. If it does not effectively communicate those messages it is not good content.
All forms of communication have distinctive syntax and structure; understanding those structures makes effective communication easier.
Pre-planning the structures that will be used to communicate a particular message makes translating the message into new forms easier.
Using consistent structures to communicate similar messages makes crafting and communicating new ones simpler.
The people responsible for creating and sharing a message have the clearest understanding of its structural needs.