I don't understand your point. A normal user has very few options when it turns out there's a bug in their off-the-shelf standalone webserver, too. They can fix

I don't understand your point. A normal user has very few options when it turns out there's a bug in their off-the-shelf standalone webserver, too. They can fix it themselves, work around it, or report a bug and wait for someone else to fix it. Exactly as in Go. Are you saying everyone should write their own HTTP server from scratch?