This.
It is very difficult to take time off at my job. We have one set of "PTO" days that include vacation and sick days (as an employee of 2 years I get 15 days per year). Most people do not take long blocks of time off, usually it's a day off here and there, maybe two.
We also have a no work from home policy. I am a web developer. Literally, my entire job can be done from a couch, and it is even frowned upon to stay at home to work when I'm sick. We are allowed to do so, of course, but upper management treats you like Judas for the day.