Because you’re expected to work when there’s no work to do

Sometime there’s nothing to do at work.

The only reasonable thing to do when there’s nothing to do is nothing.

Instead, you’re made to do something.

You’re told to mop the floors, even though no one has put a toe on the floors since the last time you mopped them.

You’re told to rearrange the stock, even though no one has laid a finger on the stock since the last time you rearranged it.

You’re told to read the policy on mopping the floors and rearranging the stock, even though the policy hasn’t been rewritten since the last time you were made to read it.

There’s no more soul-destroying waste of human life than being made to do work that’s pointless.