I find this interesting that human infants are the only ones to cry out and make lots of noise, it must have been recent historically as making yourself known to predators is generally not a good idea evolution wise.
Other primates don't cry like humans, so maybe by the time human crying became common, humans were already established as dominant predators not to be fucked with. Human babies are never left alone so a crying baby probably signaled the presence of 5-10 adult humans or more. Not exactly an easy meal.
Human infants were not left alone to go hunt for food, i believe the modern concept of family is at play here. People used to live with their parents so, much more help - much less crying.
Its mentioned in the article. Human brain at birth is not as mature as compared to other animals. Most of the animals can start walking after birth.
Chimpanzee and gorilla babies can take 4-8 months to walk. Baby chimpanzees don't cry but gorillas do (though apparently not often like human babies).