I am just trying to de-construct the factors that make Wordpress so SEO friendly - can anybody shed some light on it?
Actually, Wordpress needs some help to have really good SEO. If you look through the features list of the All In One SEO plugin, you'll see that it improves quite a number of things.
WordPress creators are obsessed with...what they call it...oh, yeah: semantic markup. Mark up = the code with which you build web pages. Semantic = can be read by search engine bots and is very descriptive as to the nature of the content to the bots. So, Google bot can easily crawl and understand the layout and the content of a WordPress blog because both Googlebot and WordPress are using standard language to communicate. They are using standard HTML and CSS.
the main reason it is search engine friendly is because (usually) the themes are cleanly coded and pages content is laid out properly header content -- header ---- paragraph -- header 2 --- paragraph 2 etc footer
Yea google does love wordpress and you can add more plugins to make your page rank higher and quicker.