The value proposition of WordPress is that grandma can run her knitting blog. Not quite as straight forward to teach nana Markdown, jekyll, the command line, SFTP... It's true that anyone who can roll their website with a SSG doesn't need WP, but those people were never WP's core audience anyway.
Only in the context of developers. For non-tech people who only wants another Wordpress or blogger, there aren't that many choices.