Yup, the game author's first effort Arm0k God of blood (or something on those lines) had a GUI and graphics.

After being disappointed with how that worked out, he decided instead to work on a world generator and fantasy story creator.

Since entire sections of game aren't in yet, and can only be expected hopefully by 2020, the idea of making an unified interface along with having graphics was dropped.

This has led to several happy and unhappy coincidences. Firstly the constant griping about how its hard to understand, both from a UI and a graphics perspective.

Secondly its created a great/stellar/benchmark setting gaming community, because its difficulty has acted as an inherent gating/filtering mechanism.

No.

It uses one of the popular code pages of the DOS era which is mostly an extension of ASCII.

ASCII: http://www.asciitable.com/

IBM Code Page 437: http://en.wikipedia.org/wiki/Code_page_437

Not really ASCII. One of the 8-bit character sets that have smiley faces, border-drawing characters and similar stuff. Check it out here: http://dwarffortresswiki.org/index.php/Tileset_repository

It's not actually ASCII, there are many more characters used. It is however "ASCII art", in that the characters are used to graphically represent places and objects.

...and it uses text in an annoying way. It renders the text in OpenGL, which is one of the reasons why a 'text mode' game is so resource intensive.