If you've been a web dev for 10 years then you'll know that the most fundamental tool for scripting is a pain point (document ready), jQuery did a good job of abstracting the nuances away, see: http://stackoverflow.com/questions/799981/document-ready-equ...
And the incompatible ajax interfaces. And the inconsistent element selection. And the...
I'm also not sure I'd call document ready the most fundamental as a lot of people (including me) used to use onclick='' and onload='' directly on elements back then when we all loaded script tags in the head.
Document ready is hardly the most fundamental “tool” for scripting, and it has always been easy to resolve in a cross-browser way: stick your scripts before </body>.
