No thanks. I've been writing .Net since before day one and quite frankly I've been buggered around enough now to run as far away from this as possible.
Of course, other ecosystems have their own versions of this. But Microsoft might be the only one that essentially controls an entire ecosystem and still manages to give devs whiplash.
"Microsoft says you need to start funding your entire product to be rewritten from scratch"
Apropos WCF, well we got JSON and no-one outside of "enterprises" were doing SOAP/WSDL et al any more and it was pretty much done. That's not really a fault of the vendor, the world moved on. At the end of the day, as a software development house you have to make strategic choices, regardless of vendor. And you can still build WCF apps today, sure maybe not in .NET Core, but they'll still be supported for donkeys years by MS, but who'd want to?
Or maybe you're saying it was DOA?
Pretty much. The only time I've ever seen Silverlight apps in the wild were for streaming use (Sky/Now TV for example).
I wouldn't use any of their flavor of the month tech they release from the conferences. But the .NET framework has been pretty stable over the last 15 years.
As for technical improvements, well... it's a language that took, what, almost a decade to add generics? And that's because the designers were claiming that everybody else is doing them wrong, and they want to figure out how to do it right. Now that they're finally adding them, turns out that they look exactly the same as everybody else's.
Besides, Go does use libc on macOS (now), and always used Win32 API calls on Windows, so it clearly can be done. It's just that for a while, they've decided that being fast on macOS was more important than respecting the ABI stability guarantees from the OS.
Just decades of over-engineering OOP "best practices" baggage that is impossible to shake off.
Why do people "move" to new languages? Mostly to leave the baggage behind.