When done right they complement each other. I'm not going to sit here and argue everyone should be handjamming their own XFree86 config file but there are still a lot of austere environments out there where you don't really get a GUI. A basic knowledge of VI can go a very long way and as long as someone doesn't go out of their way to disable terminal access the capability never stops being useful.

Kiosks are a good example of a GUI-only environment, but I'd never want to use one as my main computing environment and don't understand wanting to be limited to that world (which is not what anyone here has suggested).