People used to point to my husband at work and blame him because he had two small kids, but our kids never went to daycare, so the only place he could catch a cold WAS at work, but the people at work would always say, yeah, he's got kids, he's bringing it to work.
Such a bummer! Plus, some people are sick with the same cold differently. Right now we both have a sinus cold and he's sneezing constantly and his sinuses are bugging him; I just have a runny nose so I don't 'look' or 'sound' as sick, but I'm shedding virus just like he is. Most people are the most contagious before they start having symptoms, so you're catching stuff from people before they sneeze on you.
If my poor husband stayed home every time he was sick, he'd never have a job! I do think people should stay home if they're running a fever, because your viral load is usually extremely high at the onset of a fever. This from my MIL the nurse.
And I recommend Sambucol, which you can get at health food stores. It's elderberry flower extract, which has been proven to prevent viral replication in several studies, and has been used for hundreds of years. My husband calls it 'witches' brew'.