Is it because a higher percentage are failing, or are you hearing of more failures because there are more CF bikes on the road?
I have a friend that broke the drive side chain stay on three Trek Madone's. The fact he is 6'3" and 240#s may have had something to do with it?
I have a 2012 Supersix frame with a cracked seat tube. After a sudden stop the bike went airborne and landed on a corner of the seat. A metal frame would have probably survived.