They can encourage presenteeism (e.g. by a fixed number of sick days, policies requiring doctor notes for just one day ill) so sick people spread their germs. They can overwork you and cause stress.
In my experience, managers are particularly good at coming in and spreading germs because they "had an important meeting and so much to do."!
Ugh, yes. At the beginning of last winter, one manager INSISTED on coming in with this really horrible, wracking, deep cough, and the resultant spread managed to take out about half the management team and a ton of floor staff variously over the next month or so (including myself - how grateful I was).
I'm sure it was totally worth it for the one or two meetings they attended..
