David Ziffer wrote:

In my experience, which now spans over three decades, the apps that are the hardest to change are the hand-written ones with lots of inconsistencies.

What a coincidence - I've been at this game well over three decades as well - but only a small part of it as a DBA, with a much longer stint in application development.

You're right, it's better to use libraries and built-in functions whenever and wherever possible, which explains the success of everything from .Net to JQuery. However ...

Once again I'll use the car analogy. Which is easier and cheaper to maintain and adapt .... a custom hand-built car, or one that came off an assembly line? I'll take the Honda Civic, thank you.

Once again? I must have missed something ... I'd thought you started and ended with the Roman Legions. But regardless: in my own experience, a Honda won't get you very far after the paved road (which, incidentally, was part of the Romans' system of domination) ends and the morass begins. I'll take a Range Rover, thank you.

Or, if you prefer a more recent historic analogy than the Roman Empire, look at the US/Viet-Nam war. The US certainly seemed far more systematic and technically adept than its foe - but it was scarcely as adaptable.

Arminius and Ho Chi Minh were both very good at stopping empires in their tracks, through adaptivity ... although I'm not sure either was much good at SQL.