* It's tangible. I can put in a couple of hours of work and then step back and see exactly what's been accomplished.
* The techniques are hundreds/thousands of years old. New tools come along (not as quickly as they do in software), but at the end of the day, we've pretty much decided on a handful of best ways to do things. There's always new stuff to learn, but you're very rarely inventing something from whole cloth.
* And my personal favorite: Every project has a definite end. That jewelry box or coffee table is FINISHED. Sure, after a time I might put a new coat of finish on something, but once a piece leaves my shop it's done. I'm not forever tweaking this or that about it, trying to make it something it was never meant to be or tearing pieces of it apart to redo the joinery or whatever.