[LBJsPNS]

Vacation, sick leave, and the like are regulated by law in most states/countries.

So is work without compensation. It's somewhat frowned on. Despite your absurd false equivalence.

[listenallyall]

...and the concept of "exempt employee" -- one who is salaried, and does not receive compensation for working overtime -- is also regulated, legal, and well-accepted.

[LBJsPNS]

There is a bit of a difference between an employee who accepts a salaried position and the benefits and responsibilities thereof, and asking or demanding an hourly employee work off the clock for free.