CNC'ing a part that is subject to repeated flexing just doesn't make much sense. Better to use a technique that is fast and ensures an even, strong product than a technique that comparatively slow and can result in a weaker surface and unseen stress risers.
The 'pretty look' you refer to is what I'd call the 'fashion victim' look. You can get lots of CNC'd stems (Thomson being the obvious candidate). But reports of cracked faceplates (and discovering one myself) has thoroughly turned me CNC'd stems, let alone a more flexible part like a handlebar. Something like a seatpost is probably fine (Thomsons have a great rep there), but seatposts don't flex as much as handlebars.