Is that really so about salaried workers? Enlightened employees might work that way—though they wouldn’t give a full-time staffer an hour-a-day of work—but I was never of the impression that a salary freed an employee from ‘face time’.
That's one of the big problems with modern office work. We require more face time than productivity. Though I'd suggest that rather than spend the time sleeping, he should spend the time upgrading his skills and knowledge.
It depends upon what type of exempt from overtime salaried worker you are and what is in your contract.
People with administrative exemptions that supervise people maybe required to be on the job, etc.
The main idea is that a company can't treat a exempt employee like a non exempt employee..