And then again, they are pain in the arse (if not impossible) to use on Windows. One of the benefits of ELisp extensions is that they are multiplatform.
I agree some of them are harder to setup in Windows. But it helps (or forces) developers to make these tools and languages cross-platform, which is good, I think. And I guess making them cross-platform is actually easier than implementing them purely in Emacs Lisp.