They derived WPFs design and API language, along with XAML. Its not like MILCORE was written in C# either.
> So what does show a good measure of overall developers that shows the slow death of languages/devs without IDE's
It shows nothing. IDEs haven't really been a thing (they weren't that good until then) since the late 90s or even mid 00s. It is taking awhile, but its happening. We will see more language designs that don't bother with IDE independence for better features. Couple that in with the Bret Victor candy, and there is only one way to get there.
> There's also lots of value in small, wrist-friendly languages that don't need an IDE and have a good story for text-editors / command-line. You may want to check out what the dev story is for Clojure / Go / Node which support live-reloading / auto-running of modified tests and fast dev iteration times without IDE's.
I know all about those systems, and they aren't very inspiring. We can do much better than that if we don't limit ourselves to languages just being syntax/semantics/and a compiler.