Gall's Law for anyone who didn't know or couldn't remember it:

"A complex system that works is invariably found to have evolved from a simple system that worked. A complex system designed from scratch never works and cannot be patched up to make it work. You have to start over with a working simple system." – John Gall (1975)

Thanks for the reference, this is the best quote I've found in a long while. Strangely, I was unfamiliar with this.

Incidentally, he passed away recently. He had a varied career and was actually my pediatrician and encouraged my interest in astronomy. I only learned at his death about his contributions to systems theory...

I think it's crucial to the maintenance of our superstition that we don't know which parts of the system are actually important, and we keep misleading ourselves into the wrong assumption.

For example - style considerations. Important? Yes? Maybe? Not at the moment when it reaches the computer, but important when humans have to grok it.

So then should we "lead" development by promoting style? Will that get us somewhere? Probably not as much as some other strategy. But it's still sort of important and this blogger made a nice post the other day about style, so...

A microwave oven's input-output mapping is much more relevant than how it works. And you can get a feel for that by plugging it in and pressing the buttons.

It's a very general point - how to interact with things is often dependent on the surface, not the volume. This is the generative insight for the systems approach to engineering.