There is little to no difference in taking a child on a sailboat and taking a child on a plane. It is a means of travel. It may not be the best of ideas, but it is probably no more risky than driving with a child, or flying with one. Provided the laws allow parents to do so, it should be okay.
There is no harm in taking your baby or toddler with you on a sailboat but one should remain extra careful and take all the safety precautions in order to avoid any accidents. If for any reason you think that you might not be able to give your full attention then its better not to take your baby with you on such a trip.
Parents who know what they are doing have every right to take their children on adventures with them. Assuming the ship is in good repair, the parents have valid proof of their skill at piloting, navigation, and supplies, then yes, families have the right to adventure together. Children fly on planes and ride in cars all the time!
They should repay whatever it cost to mobilize the troops and vehicles involved in their rescue. It seems that the issue would have been avoided entirely had there been no children, specifically infants and toddlers, which kind of leans the situation toward negligence on the part of the parents. Like the sort of negligence that would get kids taken away.
The only thing they NEED to do as parents is keep their offspring alive. That alone isn't enough to call them good parents, but willfully putting them in an easily catastrophic situation is well on the other side of the spectrum.
No, I don't think parents should be taking toddlers and babies out on the sea. I understand that the parents in this situation were experienced sailors, but a voyage this far out should not have included the children. Every parent knows how quickly emergencies can arise. You try not to put your children in a situation that could turn dangerous for them.