I read the post. The language is just confusing. You shouldn't have to tell me that "You should write your next web server in Go" doesn't mean what it says on the tin.
A web server is Apache, Nginx, Lighttpd, etc. What you just described is a Web Application, which I develop all the time on python -> uwsgi -> nginx stack.
For the record, I'm not blaming you, but the author for the confusing language. The title says "Web Development in Go" -- web dev is traditionally web applications/html/css etc, not typically including servers. Then their opening sentence is "You should write your next web SERVER in Go"
/pedant
I don't think the language is the slightest bit confusing. I also think your definition of "web server" is wrong. I would say a web server is a program that processes HTTP requests and optionally responds with something (commonly HTML, but can respond with data of any format).
That includes apache, nginx, etc. It also includes programs written in X language that process HTTP requests.
“Your own web server” here means “your own program that serves HTTP requests”, and yes, people write programs like that all the time.