It really depends on the kind of media you use. I fully agree that some types of CD-Rs out there will die within 2 years.
But then again I have various CD-Rs that were burned over 5 years ago, and because I used quality media (Hitachi Maxell, Ricoh, Taiyo Yuden) they are still 100% readable today.
The bottom line is that you get what you pay for, and you should take care of your optical media if you want it to take care of your data.
If you have very important data, then burn it more than once and store the various discs in different locations.