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?

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

"Hmm this makes me wonder what did our previous generation of computer people do that had all this evil blue light blasted into their brains?"

They created things like Google/SEO, affiliate linking, facebook, twitter, pop-up ads, malware . . .