The Go team was populated by people who had created one of the most influential languages of all time, C. Who created the new language based on theories about how to encourage good engineering practice. Theories that they were able to test through internal access to a very large and actively maintained codebase at Google. A codebase into which they had inserted several other languages that they had devised for various purposes.
I'm pretty sure that nobody in the external programming languages community had the same depth of experience in the practical use of programming languages that the Go team had. And so it was bizarre to them to see the Go team deliberately leave features out because of concerns about how those features are used in practice.
Few of the critics who "knew about programming languages" have created any language that ever made it into the top 10 programming languages in the world. It is therefore funny to me that they were complaining about exactly the kinds of choices that lead to Go becoming popular.
I'll generally take the design choices of a team with 2 popular languages under their belt over academics in the ivory tower.