Look, there are core Go developers who admit that parametric polymorphism is a good idea. In fact, I'm not aware of anyone on the Go team arguing against that. Which is what you mean by "generics", right? In fact Go already has "generics" - maps, slices, channels. Are those "slow" in your opinion?

The only thing left to do is to propose a system that has reasonable trade-offs, doesn't suck, and doesn't completely break the existing language. Easy peasy!

I wonder who is doing Go more a disservice - people who hate everything about, or the blind fanatical devotees who think any criticism towards any aspect of Go is heretical.