Post a link to those stats?
http://www.electronista.com/articles/09/11/17/reliability.study.has.apple.4th.place/
3 year malfunction rate is about 17%, assume that's evenly distributed among the 3 years. Applecare covers years 2 and 3, so that's about 12% fail and are covered by Applecare, that's one in 8.
Assuming Applecare purchasers are randomly distributed among Mac purchasers, I correct my previous statement to "Yeah, but for every you there are 7 Mac users who bought Applecare but never used it.
So if you buy Applecare for $300 with a 12% chance of using it, the average repair cost would have to be $2500 for it to make economic sense. You could buy a whole new laptop for that. Hmmmm.