But a greedy company acting purely in self interest wouldn't want this because you are getting less productivity by making sure your employees are constantly tired and never getting anything done.

To get the full picture you need to shift perspective and see humans more as resources. When a resource doesn’t produce enough anymore it gets replaced.

How can you possibly develop a product when none of your developers have been around for more than a few months?

If the entire industry is less productive, it's not a business problem.

Overworked employees a probably cheeper per hour too.

Inappropriate incentives for individuals cause behavior that hurts everyone. Not exactly a new thing.