Yep, but not many are setting up standalone git servers and most people are wholly dependent on the web UI for some nontrivial organizational or personal git management. Either that, or they're using gitlab. Which is also RoR (iirc)
There’s nothing to set up if you don’t need a GUI and are already running httpd/sshd.
Yep. And people generally don't do it. Because they want things the gui. Is this even a serious argument?