Carbon F1 cars last only 1 season (if that) and are not used for a daily commute. They can be over-engineered, since its easy to build under the weight limit. Most F1 cars carry about 100kg of ballast just to meet the regulation min weight. When they do crash, they are designed to snap in places, to absorb energy.
The comparison with bike forks is not valid.
Check out
http://www.velonews.com/tech/report/...es/3270.0.html
The main concern seems to be crash damage leading to a deep scratch which acts as a stress raiser.