Yes, but what of the subbers who accept to be part of the team and then, in a 16-hour drama, contribute like 10-20 subs? Or zero subs?
I understand if someone initially says she will do the job and then something unexpected happens so she cannot do it. But that's why communication is crucial.
"This week I'll be out of town with no internet, I won't be able to help".
"This month we have our exams, so I'll come whenever I can but I cannot promise much". Or even
"I know that I was the one to ask you to be in this show, but something came up, so I cannot after all - so please remove me, it will be for next time".
What's so difficult about writing something like that so that the moderator knows on how many subbers to rely?
In my own teams, I expect subbers to be present at least once a week - even if it's not for a full part - or if they cannot, write it on our Google sheet so the rest of us know the situation and someone else including me can do more.
Communication, collaboration, helping each other and filling in for each other, that's what teamwork is supposed to mean, right? Not just everyone doing their own thing whenever they feel like it.
I sometimes volunteer for an organization that helps immigrant unaccompanied minors. They issue an email saying "a volunteer is needed for a baby in X hospital (Note: they put them in hospitals even when they're not sick): Monday to Saturday from 8 p.m. to 11 p.m." . If I reply to that email and say I'm available to watch and take care of the baby on one or more of those time slots, should I feel free to not turn up just because I'm a volunteer? If I committed, I have to go, and if something comes up, then I have to tell them beforehand so that they can arrange for someone else.
Certainly subbing a drama is much less urgent and important, but the principle should be the same, right?