The generated csv from t users isn't parsable; it contains user tweets & descriptions, which often contain commas and newlines.
Ruby's to_csv method seems to escape commas and newlines. I'm not familiar with say, but that might be what's unescaping them?
I spent a while looking into this but I'm unfamiliar with Ruby's gem system. Simply appending to_csv().html_safe might do the trick, but I couldn't figure out how to apply my changes to the global gem.