Embed Different Python Engine

Why would they step back to C++ if they’ve moved almost completely to C#?
I think IronPython’s capability is good enough. Also there are plenty libraries in nuget to cover all CPython modules. Problem is the learning curve of IronPython using .net libraries is a bit steep. At least for me. I definitely need more IronPython examples. IronPython3 is something I’m impatiently waiting for.