In an era where a face you can see is a face that could be spreading deadly/debilitating germs, no, employers are not entitled to see my face in person or to show me theirs. Obviously if I worked in a field where the job couldn't be done without having my masked face there, I'd consider it reasonable to ask me to come in--as long as others had to take precautions not to endanger my health. The sheer negligence employers display toward their employees these days is appalling.

Possibly the "bad attitude" you're detecting from your coworkers who are forced into the office is actually trying to minimize their risk of dying or being disabled due to the impulses of their sociable yet not-very-bright coworkers, and, yes, there's probably a fair amount of justifiable resentment that they may wind up very sick and if they want to be able to stay employed (eat and have a place to live) there's not a lot they can do to head it off.