Computers without one or the other would be a nightmare.
roxor: Simple GUI programming isn't too bad if you use the right tools. For example, using Glade on X11, you can build GTK+ GUIs in minutes using point and click, then generate C or C++ code (other languages too with plugins). You can also use libglade to load an XML file at runtime describing the GUI layout.
This gets rid of the easy job, leaving you to write the callbacks, custom widgets/controls, and whatever else.
Also, Graphics programming using C++ with SDL on Windows, OS X, FreeBSD, or Linux is just as easy as with DOS, only you get hardware acceleration, cross-platform compatibility, and a flat memory model. Your choice though.