That's exactly my point. If you want to host a blog today on an FTP server or Amazon S3, you need to design yourself a template and build a bunch of HTML pages

That's exactly my point. If you want to host a blog today on an FTP server or Amazon S3, you need to design yourself a template and build a bunch of HTML pages, either in a text editor or with some random desktop tool or something you rolled yourself. Then you need to transfer the files to the server, either by hand or via a script of some sort. If you wanted to do that 5 years ago, you'd sign up for Blogger and use their awesome free software to do it for you.