I think right now the idea is that if you feel sick and are running a fever that you should stay home and self-quarantine and not be at the job site anyway. To continue to go while having symptoms would definitely put those around you at risk and if you didn't make it known that you had it after being tested, then everyone else potentially has it and if asymptomatic does not know to stay home and self-quarantine so it just becomes a never ending transmission.

Personally, I would be pretty mad at someone who knew they were positive and was out and about and exposed me to it and I got sick.