At present, if a page has 2 images and 2 JavaScript files, there are 5 calls made by the browser. Sure, you can have keep alive and pipelining, but it still 5 network calls. Is there a way to send one zip file and let browser resolve the resources within the zip or similar compassed file?
5 calls is just an example. In large websites, 30-50 calls per page are are not uncommon. Also, in-lining does not help, because your subsequent pages are going to refer to individual js/css/image/icon files. So those requests should be served from cache.
Network calls matter, specially if you have a hybrid application running on cell phone, and the user is in east coast and your data center is in west coast or worse, your user is in europe and you have datacenter in west coast etc.