No one is saying generics can't be implemented in go, or that go is "special".
Implementing generics requires tradeoffs of some sort -- compile-time and size, runtime efficiency, or language-complexity. The creators didn't want to accept any of these compromises, at least for the initial release of go.
No, it does not require a trade off. That is exactly what I just pointed out. There is no such problem. Parametric polymorphism was solved in 1976. None of the things you mentioned are actual problems, they simply do not exist. Those are invented excuses. If Rob seriously still hasn't bothered to read CS papers from 30+ years ago, that is very unfortunate. But it does not mean the problem wasn't solved, it just means he is unaware of the solution.
I'm more willing to trust Rob Pike on his assesment than a random Internet comment from someone who has neither knowledge of Go nor has read the comments on their mailing list.
Appeal to authority. You don't have to trust some random comment on the Internet. Read a little about how generics are implemented in other languages today, and you will be able to see the points the commenter is making.
