Well databases have structures and are easy to concurrently write to and have all sorts of checking for wackiness of constant input and output and usually work in a client-server manner. A flat file is basically thread888098.txt

Flat files! Fuck. Honestly, that explains everything.

I liked my answer better. Flatfiles are files that have yet to develop into nice, round, bouncy files; files you need cloth and wire to support.

But yeah. There's always that too.

Flatfiles are messy, bothersome, and impossible to rewrite.

They're handy if you need to code a user-updatable website for a cheap chap who won't pay for MYSQL support though.

Anything beyond that is... not fun.