One thing I noticed when I first bought a Mac was that the driver for my Lexmark printer was about 30MB and integrated properly with the system printing options. On Windows, it was more like 200MB, had its own custom print dialogue which could be themed and had an online gallery for themes which you could download. You could download a theme that turned your printer dialogue into a potato. Not even kidding. On Mac, the printing dialogue was just the standard OS X printer dialogue.
Why is this? I don't know. Maybe they put less, er, effort into the OS X driver because of marketshare. Perhaps it was a different set of developers and the Mac developers had some sense. Maybe it's not even possible to create custom-potato-themed printer dialogues for OS X. All I know is that since moving to OS X I've seen far less crapware and whilst you're right that OS X has some UI warts too, I find that it (and the 3rd party software you install) bugs you a hell of a lot less.