LOL
Those people shouldn't put themselves in that situation! Anybody who played football as far back as junior high already knows they going aren't out for a picnic. Football is not a dinner party, a social club, its not a dance team and you're going to talk somebody into defeat.
Some days are rough; some days are rougher. And it gets rougher the higher you go. So if you can't handle criticism, walk away.
Same with you. You have a boss. If your boss says this is what you have to do to become a supervisor, you either do it, or you forget being a supervisor.
I say that being an old USMC Vietnam Vet/DAV. If you won't do your job, or don't know your job, I don't want you on my team. Because the second I need you the most, you won't do what's needed, or know what to do. And people are probably going to pay for your failure. I can't have that. So we all need to be on the same page.
Compare that to football or life or whatever you choose. But like your boss, if you don't want to do the job, I'll find somebody who will. And you can go tell the unemployment commission I'm a butthole.