Mark is onto something with his call for NeoVictorian Computing: when you're trying to do something, the #1 most important thing is that your software shouldn't get in the way. This is the "do no harm" principle applied to software design.
Specifically: do no harm to my productivity!
Why can't I have a simple tool that lets me do more actual work? I'm tired of wrestling with interfaces. It is easier, faster, and more fun to work on paper than in Word or Photoshop...