- Table-based layouts
- HTML-based styling
- Unresponsive, etc..
I believe full-page reloads will belong on this list before too long.
They are slow. That is really all I need to say. I spend a lot of time developing on my local server, where page reloads are as fast as possible, and it still feels slow after a while. Even when all the files are stored locally,there's still an amount of time that must be consumed for the browser to do a reload. And for what? Most elements on a given page, especially a blog, don't actually change from page to page. The header, footer and often the sidebar are all the same page-to-page. So why reload all those assets for nothing? It's a waste.
The other issue is that they are unnecessary. Through the use of AJAX we can accomplish pretty much anything we want on the back-end without actually reloading the page. Just send the necessary information, parse the response and update the page. Simple.
Admittedly this might not be as simple as just using page reloads but the user experience would suffer. Look at some of the largest commercial websites right now (Google, Facebook, Twitter, etc.) and see how many make extensive use of AJAX to minimize page reloads. Google's instant search and maps are both good examples. Twitter uses a ton of AJAX on their pages and Facebook, although still making use of numerous page reloads has decreased the number significantly over the years.
I'm admittedly not an expert on the nitty-gritty of HTTP requests so if anyone wants to point out an aspect that I'm overlooking, feel free to do so below.