WordPress Theme Development Seemingly Awful Partitioning of Includes?

Well, that tutorial is pretty old and out of date. It was written for WordPress 2.0; 10 major releases ago.

The short answer is: it’s done that way because it’s the best way to do it. It’s the fastest/simplest way to separate content from design and give all the control to you, the theme developer.

If you don’t want to open a tag in the header without closing it in the header, don’t. I personally always do that (although I usually close it in the footer, not the index.php file). The great thing about WordPress is that it lets you do whatever you want.

Here are two good reasons to use get_header():

1. It fires an action hook that plugins may be using, and
2. It makes your theme more compliant and therefore easier to use as a template for child themes.