Why not just using ajax for Page Requests to load the page content?

Question

Many web pages load all of their content to change very little information.

Now I would like to know why shouldn\'t the developers just use ajax for the main page re

Answer 1

Search engines, crawlers/spiders, browsers with no javascript, screen readers and other consumers of the content will not be very happy with it.

You can provide tons of ajax behavior on top of you website if you already support standard server side navigation for the full content. Have a look at progressive enhancement (SO) and progressive enhancement (wiki).