> The problem with interface{} is that it makes it pretty much worthless to have a type system at all.

I don't understand this argument. You need `interface{}` about 1% of the time; somehow it's better to have no type checking than only 99% type checking? Even in the 1% of cases, I've literally never seen a production bug (or even a failed test case) caused by a type error. I'm sure they happen, but I doubt they happen so frequently that adding in a generic type system would be a net gain.