I feel this is a symptom of people coming from dynamic, higher level languages, who may or may not have ever really learned concepts of CS, "switching" to Go for performance reasons. I don't intend to insult anyone or certainly the authors of the above.
Go is type safe but doesn't keep you from shooting yourself in the foot. You NEED to read the spec to understand when sharing memory is generally OK. I'm glad not to be penalized in performance or boilerplate to accomplish this. The downside, of course, are stories like the above.
I don't blame the language here, though. They give you the tools to be safe. Getting away from automobile analogies, let's try woodwork. I can give you a drill, a drillbit, a screwdriver, and a screw. Sometimes you should know when to make a pilot hole, and when it's ok to forego this. But folks looking for 'performance' or 'ease of use', or folks who come from languages that just give you a nailgun, will inevitably split the wood a few times.