One of the worst experience I had was fixing a project on msaccess, one of those GUI based coding environment.
MSaccess intend to provide a graphical UI to create database driven apps. I've seen people creating programs this way without having much "text programming language" knowledge, and those program somehow "do the job". As much as I hate ms access, I have to admit it give some people a way to turn ideas into computer programs, without text programming language.
At some point, the same people have more needs, and msaccess becomes unpractical for them. They need people like me (we all need money) to "fix" or "expand" their program, and this is where it turns into nighmare. Graphical UI won't do 100% of the job, and you need to add little TEXT program snipsets here and there (formulas, routines, whatever). This makes the program very very hard to maintain, having pieces of code disseminated in hundred of places, with no way to get a global view of the software.... Needless to say, this also make future changes even more complex and expensive.
This is to me one of the key feature of text programming environment: you can have a global picture of your coding, organized in folders, files, etc. You can grep code parts, find them, merge them, split them, reorganized them, comment them, keeping the whole project well organized all along its evolution.
The only thing I would like more than text file is a rich-text programming language that makes possible to add visually rich comments, designs, etc, but keeping the useful part (the program) purely textual.