Well, that's partly because these languages were never designed to be functional in nature, and partly because the approach you propose is not how FP works. I'm not sure what else you'd expect?
If someone tells me that languages are adopting a functional approach, I would expect to see the tools and methods evolve to allow functional code to be written. What I am seeing is languages adopting specific functional methods that can be used or discarded, rather than encouraging the adoption of the actual style.
