Not to mention in many cases on the original Macs, you probably didn't even have the program floppy in the drive when you were working, because with only 400K on a disk you had to swap to the disk with your document on it.
I recall Inside Macintosh had a big disclaimer at the top that warned "The Resource Manager IS NOT A DATABASE". It was originally just meant to handle localizable resources, but since it was already there it was handy for developers (including Apple themselves) to use to load any kind of structured data. And who didn't love going messing around in system and application files with ResEdit?