I had a thought at the Simple Design and Test conference.
“Simple” is an adjective, but there are different kinds of adjectives. For example, one might point at a can and say that the adjective “blue” applies to it. That use of the adjective is objectively true, at least in Richard Rorty’s sense: we use the adjective “objective” to describe those statements it’s pretty easy to get people to agree about. The harder it is to get people to agree, the more subjective the statement.
However, suppose the can contains iced coffee. I claim that the adjective “tasty” does not apply, but other people would disagree. Here’s an adjective that quite clearly depends not just on the object it labels but also on the person doing the labeling.
Finally, consider a bed labeled “comfortable”. To be more specific, suppose it’s a waterbed. A waterbed might be extremely comfortable for sleeping, but someone I trust tells me it wouldn’t be comfortable when making love, and I’m quite sure that no waterbed would be a comfortable platform for doing deadlifts. Here we have a case where the suitability of the adjective is bound up with both the person applying it and the activity they’re thinking about.
I claim that “simple”, when it comes to “design and test”, is most like the third category. In a way, when we say “that’s a simple design”, what we should be saying is “that design lets me do actions X, Y, and Z without friction and with ease.”
So: when we talk about what properties make, say, a design “simple,” we’re using shorthand: “I’ve noticed that property X is usually associated with designs that make activities A, B, and C easy.” The fact that we have a hard time getting people to recognize or desire simple designs suggests that we maybe ought to focus on understanding and explaining the activities over capturing the properties.