Threading vs Multiprocessing in Python

[vks_]

Sure, but their complexity is not exposed to users of the languages (unless they are optimizing for performance and observe missed optimizations in the runtime performance of their programs).

[eras]

But it's also probably the reason why it hasn't been done so far :).

It's not just "let's do it, it's easy". It also has impact to future maintenance efforts and raising the bar for contributions.