In your scenario, a C-only citizenship child with an A parent and a B parent is no worse off than say his peers who have C-only citizenship, and whose parents have C-only citizenship, too.
It's not like any of those C-only peers could easily visit or move to A or B, either, based on how you've described their policies.
If anyone is worse off in that scenario, it would be the C-only children with C-only parents. Those families are pretty much stuck dealing only with country C, no matter what. The multi-citizenship family, on the other hand, could potentially benefit from the ability of a parent returning to A or B for a period of time, for example.
You seem to be mistakenly portraying the family with more options and flexibility as "victims", when in practice they're actually much better off than others are.
It depends how you look at it. Sure, policies would be the same. But if you think about people, those kids may have minimal chances of seeing their extended family for years.
It's not like any of those C-only peers could easily visit or move to A or B, either, based on how you've described their policies.
If anyone is worse off in that scenario, it would be the C-only children with C-only parents. Those families are pretty much stuck dealing only with country C, no matter what. The multi-citizenship family, on the other hand, could potentially benefit from the ability of a parent returning to A or B for a period of time, for example.
You seem to be mistakenly portraying the family with more options and flexibility as "victims", when in practice they're actually much better off than others are.