The logical thing to do is to build on what other languages did, and use established practices. Comparing what Rust did to golang when it comes to generics for example is enough to show the mentality of the golang authors refusing to look at established work.
I disagree, as I remember a lot of talks and articles from Go team members where they discuss in detail established work in other languages – on GC, on language evolution, on generics and so on – and deliberately learn from them to avoid same mistakes.
The fact is Go team learns from other implementations and it's clear from talks and articles. Another fact is that you're accusing them in having the "mindset of refusing to look at established work". Those two facts don't get along together, that's why I disagree.