I don't follow you on this. You could just as well say; since Go is already in GCC I don't need another compiler to write Go and I don't need to write any D, or C++ or...
In any case D and Go are very different beasts
In any case D and Go are very different beasts
Go's compilers (like all code) also have bugs, but you rarely if ever run into them, even given their youth and the blinding rate of improvement, they are quite stable.
"current compiler is eminently usable", didn't you just concede half a sentence ago that it is now full of bugs?