These are the geek versions of "movie plot threats": increasingly unlikely contrivances of a combination of poor choices and brilliant evil genius which can only be addressed by the fact that the hero studied ballet back in high school which we know because he was razzed about it in scene two.
Bull.
Back in real life:...
Well, in my real life, I've never "rainbowed" a table, or even know what that is after 12 years in IT, but I sure can open a sql file in a text editor and figure out which field is the password.
It's a layer of defense and widely accepted as the minimum and so easy to implement it's ridiculous to argue against it, especially as a "movie plot threat".
Quick, somebody make a movie out of this: