I hate the "it's old, ergo it's bad" line of arguments. His hygiene argument, which seems to be quite secondary, is also bad. Being in the same room as someone who sneezes will also get you his germs.
The solution is not to end the medieval, heathen practise of interacting with other people in real life, but to stay at home when you're sick - parallel to keeping your hands clean, doubly so if you expect to be shaking hands.