It doesn't mention the major inconsistencies in golang at all.
Go has generics. For arrays, slices, channels, maps, and some "standard" library functions. Go has generic functions. "append" being the obvious example. Go has polymorphic functions : append, make, ... If you look at the compiler source, the type system has generics, to a large extent. It's simply not accessible to normal programmers, instead only allowed for golang's authors.
As if this is not bad enough. Go cheats the type system in thoroughly non-obvious ways to get more C-like behaviours that obviously do not improve safety or programmer productivity.
Go has shudder return value polymorphic functions. Range being the obvious, but not only example (range changes in meaning depending on it's parameters AND on what you assign the result to).
As for your boxing argument. As soon as you use reflect, you're boxing everything. Oh wait, if you use a package that uses reflect, of course you're also boxing everything. Surely that can't be much ... hmmm half the standard library uses reflect. Fmt, everything in encoding, text or html templates, rpc, jsonrpc ... No need for boxing, or compile-time function evaluation or generics (all present better solutions to this, for the CTFE solution see D-lang).
Golang even has functions with type parameters. Make and new being the obvious examples. Again, this is present in the type system (not just there, also in reflect, things like printf, ...). It's simply not made accessible to us lowly go programmers.
So can we please stop with the crap that generics aren't necessary ? That nobody uses advanced type system features ? Or that polymorphism isn't necessary ? It's crap, and obviously the golang authors don't actually believe that. They just think that only they can be trusted to write such functions and that their datastructures are all anyone ever needs. If you disagree with that assessment (and everybody will, soon) Go is not for you.
So Go is simply a throwback to pre-80s programming languages, and a perfect illustration of the frustrations that led to the development and extension of the C++/Java/C# programming languages. If you give people the minimal implementation of sorting an array of structs, it becomes blatantly obvious why other languages are necessary.
The more I write Go, the more I yearn for C++. There is nothing in the C++ language that I can't do for my own datastructures/functions/... That is a huge feature, and may I just say :
From my cold, dead hands !
Btw : there is a better solution to generics as well at compiler-level, that is used in things like the CLR. First, generate unboxed versions of functions where that makes sense. If specializations are possible for 1-bit, 1-byte, 2-byte, 4-byte and 8-byte primitive data types, expand those. Then for anything bigger, like structs, create a boxed implementation, because for structs there is no longer any advantage to working unboxed. Then make it possible to pass in the version to be used in a parameter, so you don't have a combinatorial explosion when many type parameters are given.
e.g. http://research.microsoft.com/pubs/64031/designandimplementa...