Moving it to an extension seems like the sane thing to do!
That way:
1.) the functionality wouldn't be gone forever with no way for anyone to use it
2.) the community could maintain it and fix and eventual incompatibilities with the main engine
3.) the engine developers could focus their efforts elsewhere, better spending their limited resources
4.) the quality of the plugin would be proportional to the size of the community; if people care, it'd survive; if not, then no effort wasted
Of course, personally I'm in the camp of people who want to use a general purpose language like C# for game programming due to its wider ecosystem, about which I've written here:
https://news.ycombinator.com/item?id=32274504That said, it most definitely takes effort to support it as well, so if it was to be dropped in the future eventually, in favor of only supporting C++ or GDScript as first party languages, I'd be understanding, similarly to how one might want to have 3rd party bindings for Rust or Lua or Python or whatever without the engine developers having to care about it too much.
I think something like that actually happened to Boo in Unity: https://blog.unity.com/technology/documentation-unity-script...
That said, having any visual scripting capabilities is pretty cool, like for use cases such as dialogue trees, state machines, shader graphs etc. People generally seemed to think rather highly of plugins like Dialogic for Godot: https://github.com/coppolaemilio/dialogic/blob/main/addons/d...