"Anybody who wants more complex and subtle filesystem interfaces is just crazy. Not only will they never get used, they'll definitely not be stable." I think there is a more universal truism here - that "complex and subtle" are sources of pain, problems and headaches. I want to write "cool" and "magical" code as much as the next person, but that's the stuff that I look at later WTF because I am no longer in the same…
As the complexity of the projects I work on has increased (especially in the time since I became a part of a professional dev team), I've come to realize that most of that tricky, complicated-looking code I had read years earlier was actually kind of the easy way out. When you are just trying to get stuff done, the complexity of your code mirrors the complexity of the project. There's no effort put in (and often no time to do so) to create a smoother interface to shelter the code from the complexity of the task at hand.
It's much more interesting to me now to be faced with a complex task and to figure out how to make the code simple and clear. Elegant, well-designed libraries/APIs belie the challenge in writing them. The code looks so simple that it feels immediately obvious as you're reading it. I've come to realize that reading a code base that seems dead simple -- so simple anyone could instantly understand it -- is actually often inversely related to the difficulty in creating it.
Yes, necessary complexity does exist, and sometimes there's no way around doing something fairly nasty in your code. But as an ideal to strive for, I find 'simple' to be fascinating.