"Ability to satisfy user's actionable needs"... Oh please, there's a million ways to satisfy actionable needs. Just how are you going to measure user satisfaction with the design you've chosen? A yes/no survey? Your bosses opinion? Your colleague's opinion?
How about showing some guts and using your own intuition! Your own preferences, feelings, thoughts, emotions, visions, all that SUBJECTIVE fuzzy stuff. Don't be afraid, it's what humans are good at, particularly creative humans and artists, and it's how good design happens.
The logical, rational, "satisfying the user's needs" part of design, is the easy stuff. Even programmers who are usually afraid of design can figure out logical IA and a sensible UX.
The same conservative scientific argument can be applied to all art, including all the weird stuff we see at the biennale. That is, "it can be measured by the effectiveness with which the viewer engages or responds to the work, and how the artist communicates meaning and expression and...." Yeah yeah. Sure. We could attempt to evaluate the piece that way, but how about we just use our built-in subjective powers instead. And we'll get a better outcome as a result.