Good point, I definitely agree that the rights of minorities need to be protected. Some problems with this idea are with defining what are rights and what constitutes child abuse, and what to do about abuse.
The extremes of social isolation that some of these kids endure falls on the abusive side of the line for me. I don't know what to do about that, it's a hard problem. Becoming less socially acceptable to behave that way among American adults seems like a reasonable step in the right direction.
To answer your question, I think it would also be best for the scientist parents children to interact socially with other local children in rural, bible-thumping Arkansas. If they wanted to home school their kids that is their decision to make. Humans are social animals however and a reasonable amount of real world social interaction is important.
It's easy to forget that sometimes whole communities of people - sometimes millions of them - have values different from ours. And that there are people like us who are minorities in those communities. You can't protect the rights of those minorities without also protecting the rights of minorities within our communities, as strange as their beliefs may be.