> There are some other oversights too: lack of immutability/const qualifier

Not oversights but deliberate decisions.

http://commandcenter.blogspot.de/2012/06/less-is-exponential...

- constants are just numbers

- no const or other type annotations

Type System Tyranny

- Clunky typing:

- Makes programming harder (think of C's const: well-intentioned but awkward in practice)

http://html5tv.rot13.org/goog-go.html