Having a self-contained document-type is the cornerstone of sharing/remix culture. If you want people to be able to post your neat animated-SVG infographic to Facebook or Tumblr or Imgur or wherever—or to make some derivative of it with a meme plastered on top (and you probably do)—it needs to be able to be right-click-downloaded as a single file, edited as a single file, and then re-uploaded as a single file.
