The fact that Intuit owns Mint was a big part of the reason I finally caved and signed up. They're not inexperienced with dealing with private information.

Yes, on the "banks should be required to provide a secure, open feed" (though good luck in the one chosen resembling any modern format).

But... securing information of this kind is not rocket science. Sharding secrets into multiple tokens split across minimal service machines, etc. It's just that best practices are so rarely followed.