> UI needs to be approachable, useful, and unobtrusive. i.e. "forgettable." Many designers absolutely can't stand the idea of designing stuff that no one pays attention to; but that's actually exactly what most UI needs to be.

You can be all those things without being forgettable. What matters to the user is the cohesiveness of the whole experience, not individual widgets. People use apps, they don’t just stand there looking at it like a video playing.