It's not good D.R.Y. to reinvent a binding library for each and every application language. What's needed is a state-ful GUI markup standard. Then any language that can emit and read XML can use the GUI kit/browser/component, no binders needed.
Having a machine format that describes the interface and facilitates auto-generating the bindings, like GObject introspection is a better option and exists today. Even then the auto-generator will need to be custom for each language, to handle integration with the language's standard library data structures, memory management and the like.
Experienced engineers know D.R.Y. has it's uses, but isn't a good hill to die on.