[lonesword]

My guesses:

1. The previous generation did not have laptops.

2. The previous generation did not nearly have as many programmer/hackers/<late-night-computer-user-moniker> as we have today

3. Because of #2, nobody cared if a really small percentage of the population lost sleep due to blue light?

[djmips]

I feel you've forgotten phones. A majority of people have a phone that they can stick in their face in bed.