i DONT get this attitude of Google. even MS uses jquery but the open source king Google do not. is this so hard to improve upon Firefox or Ubuntu or even much less complex jquery?
Closure existed well before JQuery did.
It's non-trivial to switch an existing system over to a new JS library. I tried most recently last month, but there're a bunch of engineering constraints that made it apparent, even to me, that it was a bad idea.
JQuery is still used a lot for prototyping, where we don't face these engineering constraints.