I believe that we often put too much focus on the material and not enough on the design used to build a bike with the material.
For example steel bikes include anything from heavy straight gauge tubing to 10/7/10 tubes to ultra thin 7/4/7 tubes. Large diameter 7/4/7 tubes are .4mm thick for most of there length and when used in large diameters make a very stiff fairly light bike. In my book the very large diameter 7/4/7 tubes used by some builders are not durable because they are easy to crush or dent like a coke can. Steel is generally pretty durable as a material but the design of those bikes sacrifices the durability in the name of stiffness and weight saving. Designing the bike with smaller diameter tubes would make them much less crushable but the bike has more flex. Using large diameters with thicker tube walls would provide stiffness and durability but add weight. In the bicycling industry today added weight usually means a drastic reduction in sales volume.
I know much less about carbon but if I have read Craig Calfee's writing correctly a similar situation exists for carbon bikes. He has chosen to design his bikes with smaller diameter thicker walled tubing to provide for durability and as a result doesn't build as light a frame as many others. Those big tubed light weight single frames are not nearly as resistant to damage as a Calfee. For example below is a quote from his web site regarding the 953 gram dragonfly frame:
Calfee Dragonfly weighs only 2.1 pounds in a 54cm size, delivers power as well as any large diameter, thin wall frame, has superior vibration dampening, compressive and impact strength, and is protected by a 25 year warranty
Contrast that approach with that used by Cannondale:
....It actually gets lighter. The blue-and-green color scheme on the Team model actually adds 120 grams to the the bare 695-gram frame. .....
Cannondale's frame is stated to be 258 grams or 27% lighter than a Calfee Dragonfly and the Cannondale uses a larger diameter tubes. It seems reasonable to conclude that the Cannondale's tubing with 27% less material spread over a larger tube diameter would not be as resistant to impacts as the Calfee frame.
Not all carbon bikes are alike just like not all steel bikes are alike so it is hard to talk about materials without looking at how they are designed and manufactured.
I have been impressed with Calfee's careful design. He doesn't build the 650B low trail tandem that I want but if he did I would be tempted to buy one.