Consider the audience: this document was written for the contributors to the Go project. It wasn't intended to be on the front page of Hacker News. It's not try

Consider the audience: this document was written for the contributors to the Go project. It wasn't intended to be on the front page of Hacker News. It's not trying to convince anyone that Go is good and C is bad. It's just explaining the rationale for the move to Go. For the intended audience, these statements are pretty much self-evident, or we wouldn't be working on Go in the first place. Also I think you severely underestimate the benefits of memory safety.