Do you know that general signs such as eat, sleep, play, etc. are called baby signs. Many people get mixed up between Baby Signs and American Sign Language, but they're not considered the same thing. Baby Sign is taught by seeing and hearing parents, and they have zero relationship with the Deaf community, aren't familiar with Deaf culture, and aren't good in American Sign Language.
So why help baby learn sign language?
Being Taught Sign Language as Babies Encourages Open Mindedness
The Deaf community’s primary language is American Sign Language. Once the kids become older, and they want to keep learning American Sign Language, they will also learn more about the Deaf community and culture. Children will most likely stumble upon D/deaf people sometime in their lives, and when the hearing kids know basic signs, it can better their relationships with D/deaf people.
Learning Sign Language as Babies is a Positive Addition
When babies learn Baby Sign, this might lead to wishing to learn American Sign Language when babies grow older. In addition to English and another language which the family uses, they would know American Sign Language as a third language, which in turn can better their cv's.