Probably the most important feature of a systems language is the ability to predict and manage resource usage, and even though garbage collection is pretty good

Probably the most important feature of a systems language is the ability to predict and manage resource usage, and even though garbage collection is pretty good these days, it's still a feature that will turn a good number of people off from considering Go to be their go-to systems language. Some might not even consider it a systems language for having it, let alone a great one. It is mostly a feature of convenience, after all.