In reply to Kaiser.

To put what $rarst and $kaiser said in my own words, If wordpress wants to be an application framework, well there are better alternatives that do not carry the baggage of historical decisions and the need to retain backward compatibility.

WordPress is a legacy tool, and there is actually nothing wrong with that, its power comes from the knowledge accumulate about how to spice it up, whether if it is in tutorials, themes, plugin, thousands of people with all kind of levels of understanding how it works.
You can not just decide “wordpress is a cool web app platform” and by magic transform all of that into something that will support it. Even the obsolete codex is still coming in google before the “new” dev site, just an evidence how hard it is to **successfully** change course when you have such a big momentum.