I think some of those "Go lacks feature X" are the arguments you're eager to hear, and not simply invalid. Go lacking generics but having generic map/array types built in is an example of going against the Scheme school of thought. They're not built up from primitive features, but handed down as language features.
In addition to those, there is Iota. Which is completely special-cased syntax sugar, which is not reusable outside of a single context. You can't use it at all more generally, and get potentially non-obvious code from using plain integers silently.
I think this post makes those criticisms well: https://www.quora.com/Do-you-feel-that-golang-is-ugly/answer...