Speaking as someone who just (today) was migrating game entity data from JSON to CSV, the main reason I can see to use CSV so you can edit in Excel/OpenOffice/L

Speaking as someone who just (today) was migrating game entity data from JSON to CSV, the main reason I can see to use CSV so you can edit in Excel/OpenOffice/Libre/etc. If there was a decent visual tool (or chrome extension etc) for editing data in a format like this new one, I'd probably jump on it, but otherwise it seems like anyone currently using CSV might as well stick with it.