Not having worked with WP in a couple of years, I actually downloaded the latest wordpress to see what the code looks like these days just to see if it had been improved much (edit: before I posted my original post). For each line of code, you can roll the dice - is this line part of the presentation, is it part of application logic, or is it part of the scaffolding ? It's essentially random on a line by line basis.

Example ? Check out this file:

http://core.svn.wordpress.org/trunk/wp-admin/edit-comments.p...

there, you will see SQL statements, tons of application logic, as well as HTML output rendering. A large amount of the HTML rendering is additionally not templated but rather a long line of imperative string concatenation calls. It's all the worst examples of what PHP has encouraged, all in one file. The enormous quantity of source files present in Wordpress, most of them non-self-explanatory, is a product of this style of design.

wow.. that's hideous.. thanks for that link!