That assumes the server has a lot of additional CPU power to serve the content as HTML (and thus do the templating server side), whereas with XSLT I can serve XML and the XSLT and the client side can render the page according to the XSLT.
The XSLT can also be served once, and then cached for a very long time period, and the XML can be very small.
The XSLT can also be served once, and then cached for a very long time period, and the XML can be very small.