Here's the real question: why have backup disc sizes stagnated? We went from CD to slightly larger CDs, to DVDs, then double-layer DVDs, but BD-Rs haven't real

Here's the real question: why have backup disc sizes stagnated? We went from CD to slightly larger CDs, to DVDs, then double-layer DVDs, but BD-Rs haven't really taken off and we ought to be at something much, much larger by now.