This is how it should be, but with some employers aggressively punishing people for being sick (e.g. docking pay, forcing make-up time, outright firing people f

This is how it should be, but with some employers aggressively punishing people for being sick (e.g. docking pay, forcing make-up time, outright firing people for "poor performance") there's no incentive for people to look out for anyone else. Instead come in, muddle along, and infect everyone.