There's nothing to add for what its creators stated: Go is meant for under-average programmers, not for professional software developers.
It depends on what benefits those language features have. More often than not, they do not provide benefit to your business.
Plenty of professional systems are built in Go. This opinion that Go developers are subpar is silly rhetoric. It is not meant for everything, but for distributed systems it is great.
I don't think so. But it's a fact that Go was meant for sub-par programmers.
Seeing the kind of usage go is known to have inside Google, and how is generally accepted that Google hires only the best engineers, this fails to be consistent. I doubt it very much that anyone involved in Go development has said anything that can be interpreted anywhere close to what you said.
Also, to continue being pedantic I must say that by definition every programmer that gets paid for their work is a "professional software developer" despite the hyperboles grandparent seems to be fond of.
Go also made the fantastic decision to design in concurrency as a primitive... And then kinda for on the hill of generics. There's a lot to be said for choosing the right set of features, keeping the code readable as a first priority, and letting libraries handle the rest... Need a lathe? Import lathe!