His is an extreme case of "no true Scotchman" ("no guy that truly tried Go complains about Generics...") and confirmation bias (since those that stick to it, are happy with the status quo) together...

Lots of people have both tried Go, legitimately, and are still concerned about lack of Generics. I've read several that have done so, and have tried it myself and would like Generics. But sure, I could use it, and even enjoy it, even without Generics. That doesn't mean I'm perfectly happy with the situation.