Why doesn't OS X migrate printer settings after clean install?
No, printers are usually transferred when you restore a backup using backup software such as Time Machine. As you haven't specified a backup software, I presume Time Machine, in which case the preferences should have been transferred. If you have used other backup software, make sure that the preferences have been backed up and restored correctly.

With regard to the drivers, these should have installed automatically too, unless restoring from backup restored the drivers too. Again it depends how you have backed up, but in conclusion, neither of these situations should have happened, but they're pretty minor and have been solved anyway.