> lets not forget that the Go team made the same blunder made by Java

To be fair, they were working on parametric polymorphism since the beginning. There are countless public proposals, and many more that never made it beyond the walls of Google.

Problem was that they struggled to find a design that didn't make the same blunder as Java. I'm sure it would have been easy to add Java-style generics early on, but... yikes. Even the Java team themselves warned the Go team to not make that mistake.