That’s because that’s an easily broken and boorish way of accomplishing templating. Dreamweaver/Constribute templates require that the Dreamweaver program keep tabs on all of the files that implement a particular template. It uses HTML comments to delimit editable regions and replaces all the page content except for those areas when an update is made to a template.
I think if you’re going to be hand-coding using Espresso or Coda, you might want to implement some kind of back-end templating, since neither supports Dreamweaver templates. Both support plugins so perhaps someone has implemented this feature, but I wouldn’t bank on it. Dreamweaver tries to make “dynamic” features as simple as possible to designers, so the program handles a lot of tedious work (like replacing templates in hundreds or thousands of files) to allow designers to avoid learning anything about it.
Virtually all decent websites these days use a dynamic back-end to allow the developers to separate the content of each page and the templates, so they can re-use certain page elements throughout the site, and it also allows them to include partials and components very quickly. In fact, my web application frameworks have built-in helpers for doing exactly that, like Ruby on Rails or symfony. I’m not saying your site needs to be rewritten to use these frameworks (they serve a very particular purpose), but I think you should be compelled to look at using some kind of templating system or just plain old PHP (or your server-side language of choice) to implement templates.