^ My guess is that it's pretty much written in as a loss. Many of the companies here that offer sick time are large employers which hire hundreds if not thousands of people nationwide. They would definitely lose money trying to do this, rather than just letting everyone have their sick days.
Also companies are now doing away with sick days. I've personally only worked for one company which still used sick days, and it was only two or three days worth. So it wasn't really intended to be used to take an entire day off, but rather for taking a few hours off at a time for doctor appointments. And they could ask for confirmation of the appointment anytime, although they never did, not for me at least. Now many companies use PTO, or paid time off and it's up to you to manage your sick and vacation time.
This is good for people like me, who only get sick once every three or four years, because typically PTO has slightly more days than when they divvy'd up vacation and sick days. I never got to use my sick days, because I never got sick. I'm also one of those horrible people who never goes to the doctor, so I couldn't even use it for that either.