Looks like you completely missed the point of the "challenge". This is reproducing a real-world situation to figure out what solutions different devs will think of first.
Though I guess "complain about the situation" is a valid answer to that question.
In 2015, we continue to develop incorrect CSV parsing and production when there are ready solutions in the wild for the spec (http://www.rfc-editor.org/rfc/rfc4180.txt - 2005), such as Ruby's csv package, Perl's Text::CSV, CL's CL-CSV, and so forth. It's a solved problem. I quite understand this challenge, but this issue is important to me because this same print "%s,%s\n" stuff shows up in the wild from professional developers who have the time on their hands to use the right tool, some of which I have personally worked with. Perhaps, like in this challenge, they are under pressure to get their feature finished, and this is the first thing they think of because, after all, it's just "comma-separated values".
This challenge is especially amusing in that it, were it a real-world situation, involves people's financial welfare, and developers in a rush could very well have screwed it up. Isn't that cause for worry?
Though I guess "complain about the situation" is a valid answer to that question.