Move the scenario into the workplace.
Your work requires two teams to work on a project, someone is selected to head each time and is stands in the office and has to pick out of the people there.
The last two are met with groans and moans and mutters and evils, neither team captain wants them, they're not popular or not particularly brilliant at this thing...
Thats a matter for HR and a case of bullying in the workplace, not 'you need to learn to be resilient'..
It also wouldn't happen, asides from the above, you would not BE in a workplace together with a bunch of other people, if your skills at the thing you all have to do, were so significantly worse than the others that no one wanted you on their team!
None of the people saying it prepares you for life or its necessary in teh adult world has given a comparable example of something that truly happens in the adult world... because it doesn't bloody happen, because it shouldn't happen, because it doesn't help anyone and does cause harm.
Oh and I can tell you what happens when the kids who moan and mutter get caught by the teacher... I got a slapping from the kid who got a detention after the teacher heard her say 'oh no not that fat fucker*' to me as I plodded over to their team.. but quietly, after school where no one saw.
Great. Well dealt with.
(*and in all honesty the detention she got was for swearing, not for the bullying!)