Go absolutely has this feature. Just not for you as a user of the language.
> It has some built-in operators that can operate on multiple types.
Go has multiple builtin functions which abstract over type parameters e.g. close() can operate on any chan, append() or copy() can operate on any slice. They are not operators (symbolic or keyword).
> Most languages have this. The arithmetic operators in C, for example, can take operands of many different types. This is not "generics".
It's overloading, +(int, int) and +(double, double) are separate functions under the same symbol. It's an orthogonal feature, so much so that there are plenty of languages which do have userland generics and don't have overloading.
> This can't really be the right explanation given that generics are now being added to the language.
The core team has been saying they're considering the feature / issue pretty much since the language was first released. You'll have to excuse me if I don't hold my breath.
