5 Years for baby murder?

How shocking is this a baby not even year old was murderd by its parents by being punched in the stomach,The parent were drug users and even when the baby was born they found tracys of drugs in its urine.The crunch is they got 5 years what are the judges thinking off.In my opinion the sociel services that was dealing with this case should also be punished.Any child born to drug users should be put into care for its own protection.Whats your thoughts.