In which way does a generator manage content? The user manages content on the file system / git. A static site does not manage anything.
Wordpress is really more of a blog management system with page editing features. It doesn’t work well with different types of content, it’s geared for articles and ”pages”. How would you use it to build a site where a lot of content comes from some other background system, say NewsML feeds for example? It is possible, but you can only import the content as posts, and you only have one schema for what a post contains.
I think you should re-read the OP's original link again. Aether is not just an SSG, and its admin interface provides a CMS interface.
And I'm afraid your definition of a CMS is your own, and not the consensus. A CMS doesn't need to consume external sources, it can be self contained content.
Wordpress is really more of a blog management system with page editing features. It doesn’t work well with different types of content, it’s geared for articles and ”pages”. How would you use it to build a site where a lot of content comes from some other background system, say NewsML feeds for example? It is possible, but you can only import the content as posts, and you only have one schema for what a post contains.