I have a lot of different feelings about this and, I hope, valid perspectives. I am both the mom of four kids and the foster mom of sixty-four foster dogs (and counting!). We have gone to great lengths to try to screen out foster dogs for aggression, especially when our kids were young. I also know unexpected things happen; I have a close friend who was the most dog-loving I know who had to rehome her dog after he unexpectedly became aggressive after the birth of her son. So I think I can see all sides.
I don't, though, understand why other things weren't tried before this decision was made. Perhaps this couple was genuinely terrified (and then furious) at the nip their dog gave their child; I understand those feelings but don't think it's right to make a decision based on them. Turning the situation into a public event was hard to take.