I’ve actually used this in prototyping in the real world.
The code to read in CSV file is quicker and easier than implementing an XML parser.
I can create a nice interface in on one sheet of in a spreadsheet program that the designers can tweak game balance all day and all night ;). Using scripting or similar you can make this have a nice GUI. This generates the data.
The other sheet is just a set of numbers or key value pairs sheet can be exported into a CSV file that the game loads.
Now I can get on with fixing bugs while the designer designs :)..