You're wrong - json has types - it's very very useful just because of that, and pass newline delimited json through gzip and you basically remove all the size redundant keys...

I think this guy did the right thing for what sounded like essentially a one-off job to test this new export tool. Why would you go to all the trouble to use a SQL database for a one-off thing that can be done using text processing or worst-case writing a small script?