Server core still has a GUI, it just doesn't run Explorer as a shell and doesn't have a bunch of GUI programs that come with Windows included. When you log in there's a cmd or powershell window floating there with the standard-issue non-themed graphical chrome.

The problem with Server Core begins at the description:

> "Server Core is a minimal server installation option for computers running on the operating system. Server Core provides a low-maintenance server environment with limited functionality."

Limited functionality is the key. In order to administer windows server, one is expected to use remote desktop. This is in contrast to a unix machine, where everything can be controlled via command line and configuration scripts.

It is getting better, as Powershell exposes a lot of functionality. But it is still not there yet.