The criticism that the goblin goes after adults as well as babies

One critic panned the film on the grounds that: "the reasoning behind the random killings is terrible. If the goblin hunts babies why does it lay waste to random people with no babies? Totally retarded."

Answer: The goblin's prime directive is to kill babies in light of the curse on the village and because infants represent undefiled new life and potential.

As for laying waste to random people, the old man clearly points out near the end that, because the goblin hunts babies, it sniffs out the scent of infants on any person who's been near one; hence, his attraction to the girls who were babysitting the baby Nathan.

The goblin is obviously a demon, a minion of the devil, do you think a demon is going to spare the life of anyone who gets in its way? What's the purpose of demons anyway? To "kill, steal and destroy." Hence, the goblin was excited at the prospect of extra people to terrify and kill.