Ask HN: Why don't more blog widgets use AJAX?

My startup (http//scribnia.com) is building a widget that bloggers can embed in their sidebar to enable their users to rate them. We're relying heavily on AJAX to make the rating process more powerful and slick. Among other benefits, using AJAX allows a widget to have multiple "screens"--when a user does something in the widget, the content of the widget changes appropriately.

As per usual, I scoped out all the popular blog widgets as a prelude to the design process in order to see what best practices existed. I was struck by how few widgets use AJAX, or even Javascript. Nearly all blog widgets are just static links, text, and images. Why is this? Am I missing something here?