I worked at such a place also. Except the lock was installed when I showed up. I thought the owner was being 'cheap'.
Then I got a key to it and realized how many times people wanted me to change it. THEN I realized the actual issue. So I figgered out the same thing as Mas , but in reverse.

/but I ain't pointing at any gender; age seemed more of an indicator to me

I do not work here, but the benefits are still awesome
Make your sound your own!