GUIs might be easy to use (e.g: IIS manager), but when you have to manage 50 machines, programability is important and automation becomes more important.
Now you can do a GUI-less Windows server install, as manage it completely over the CLI.
Never mind that with Windows 10 there is no damned way to tell Windows to request a new address from DHCP if the initial attempt failed. The only way to do so is via the CLI and ipconfig.
In Unix, "everything is a file", and what is not a file, is a program that can be configured or a CLI with arguments that can be passed in programatically.