The DOM is indeed too low-level. We need higher-level components, and the ability to develop custom components. We also need a way to firewall segments of a page, so we can reason about it at a higher level of abstraction. This technology is coming, it's called shadow dom ( http://glazkov.com/2011/01/14/what-the-heck-is-shadow-dom/ ).

I've been developing a 100.000 line single page javascript app for the past few years. You can't build an app like that if you code at the level of dom elements. Encapsulation and abstraction is essential. Because the shadow dom didn't exist i used extjs as a crude alternative (extjs's component framework is really nice, but the dom structure it produces is ugly). However, with shadow dom I can imagine a way of writing javascript in the large without needing the heavy abstraction layer that extjs provides.