Was told to let a coworker handle an analysis for a piece of work. Explained what I used before for a similar job in the past. Just spent 8 hours working through and cleaning up the horrible mess he made because he thought I needed XLS when I asked for CSV, cause it opened in excel. Let's split the millions of rows across 6 columns in 8 worksheets . . .
Why? I could have just loaded the CSV into the script that builds the visualization.