Yeah, a real crash is going to result in a properly unrideable bike, no matter what's fitted where.
On balance though, a decent set of c'bars will prove their worth over and over again for the majority of mishaps that would have resulted in a holed casing bad enough to stop the trip dead in its tracks.
I've been convinced of their worth since the early days of Japanese fours when I saw how vulnerable the end casings were, and heard / read many tales of v. expensive damage caused by minor tumbles. The clincher was when a friend of mine slid down the road on his fairly new CB750 (one of the first in the country) and the damn bike was nearly a write-off because of the damage suffered.
Yet, to this day, some people won't fit them 'because they don't look cool'.
Hah.