[throwaway415415]

Because they are easily abused (look at c++) and makes code unreadable. Working around generics usually make the code clearer and thus more secure

[latronic_notron]

Go has interface{}, which can be abused as much as generics for the same purpose, but without the type safety, hence, less secure.

And nobody is advocating C++ style template metaprogramming. There are much better implementations of generics, as acknowledged by Russ Cox himself.

[throwaway415415]

Usually interface{} is abused by java programmers. I agree that it's not great, but if you don't come from java or c++ chances you won't follow these patterns at least.