Just seen the arguments for and the arguments against. To be honest, I think it was a brave and right decision.
The main argument against seems to be the rights of the little girl. Well, if she is not capable of forming the understanding of the rights, then such power must fall to her next of kin, which they have. Therefore, hers rights have been adhered to not breached, if that makes sense.
From what I understand, both hers and her parents lives will be better off.
In a nutshell, how has the life of the little girl be ill fated if she has the brain of a 3 month old?