My educated guess would be something along these two threads: * Higher data density => tighter tolerance => same physical degradation is more catastrophic (DVD

My educated guess would be something along these two threads: * Higher data density => tighter tolerance => same physical degradation is more catastrophic (DVD ~7x density of CD, BD-R ~20/10/5x DVD density = up to 140x CD density) * Produced later and therefore like all consumer goods, less regard for durability and more regard for absolute cost optimization