I, too, am sick of open source software that's poorly documented and never works. Fortunately, I use open source software that is quite well-documented and almost always works.

What's your beef with jQuery? What better closed-source JavaScript libraries are there?

How is JSON even relevant to this discussion?

Why use the disaster that is Joomla as an example of open source when you could have picked any number of other good CMSs? Besides, Joomla uses MooTools, not jQuery.

Maybe you need to reevaluate the landscape.