Good comments by Ben...

Dean, I believe its part perception which may not be completely grounded in fact as you imply. I sure don't believe Ti is really any more bulletproof than Steel or Al.
But compared to carbon because the matrix is a resin aka polymer or plastic...this ties in a bit to perception as well...metal is more robust than plastic. But is it really?
Boeing makes an airplane out of carbon fiber for example.

The knock on carbon fiber is abrasion resistance which is true...carbon scratches deeper easier than a metal frame...but also impact resistance which really is a bit of a bad knock. Yes carbon may crack based upon a hard crash, but metal will pretzel under the same forces. Both frames end up getting trashed.

I have owned every material and had great luck with each. I like them all honestly. I prefer carbon fiber for pure performance in a frameset and Al for best performance per dollar. I find Ti to be a bit heavier...and steel...if either frame is built with durability in mind.

My current carbon road bike is now about 6 years old and has about 40K miles on it. It still is in perfect condition. I have had two crashs riding since owning it where I went over but didn't hit anything. I don't have any plans to replace it current time. I know good riders with 100K miles on their older carbon fiber framesets...these guys ride a bit more than me and I ride about 5-6K miles per year.