Why PyRoom instead of $EditorOfChoice?

"I can have a full screen text editor by using a terminal, or the tty interface (Ctrl-Alt-F1) and running my favorite text editor! Why bothering reinventing the wheel?"

Yes, you can.
But Joe User can't. There is no way to force people using the console and its tools if he/she doesn't want to. Obviously, geeks are capable of using any text editor, put it full screen on the desktop, and starting to write. But not all of us are power users.

GUIs are relevant for Joe Users, because it lowers the entry level to Linux and its distributions. And we may gain more and more users by offering alternatives to proprietary software in a graphical interface, even if this is possible via the console. When they'll be über-geeks, they may switch to power tools.

And, by the way, if you are too geeky to use PyRoom, don't bother. I won't be sad about it. Just enjoy the right tool for your right job: the tool you're most familiar with, and enjoy the right to have a choice.