writing desktop UI is really difficult these days. I mean i'm not saying it used to be easier, but the amount of technologies you can use to write a web application or desktop/javascript application and easiness of creation is overwhelming, while the amount of GUI frameworks stays the same, while some of them are decaying (no new version for a long time).
So we have objective-c/swift (new!) for macos, MFC for MSVC++, WPF/UWP for C# - all those for windows, and we have QT/GTK for Linux and de facto multiplatform. That's basically all usable at the moment, but GTK is heavy on windows/mac in my opinion.
New languages bubbling up from the opensource ground meanwhile do not offer many bindings for those above, while QT had made it hard to do any reliable binding at all, apparently...
Writing c and go, and using c bindings is pretty painful compared to just writing go. It's technically possible
Just like being technically correct, it's the worst kind of correct/possible.
Qt framework is not about C++. It creates another language inside with different mechanics. And most important, different memory management patterns. Sometimes the objects are managed by Qt parent object, sometimes not. I wouldn't commit to a project that would create a GUI in Qt using CGO.
In my opinion the language itself lends it self pretty well for GUIs. The concurrency and synchronization primitives are strong.
The problem would be to have native bindings to the GUI elements of the various desktop OSes. Which are hard to build as calling C or C++ libraries aren't a real option.
I would love to hear why Go as a language isn't suited for GUIs. I've built a couple of toy GUIs and it's been a pleasure doing so.
The GUI situation in go is poor, but other than that I would say go is an excellent tool to write the remainder of the IDE in.