> It doesn't really matter. Your suggestion is worthless in practice with Go since "your subtype" doesn't enable polymorphism.

I never said that struct embedding creates a subtype. I said that it can be used to emulate inheritance (subclassing). Inheritance and subtyping are very different things, and the fact languages like Java and C++ conflate them actually creates several problems. See:

[0] http://www.cs.utexas.edu/~wcook/papers/InheritanceSubtyping9...

[1] http://stackoverflow.com/a/23592298/46571