I understand why sign language advocates push for families to learn and use sign language with their deaf and hard of hearing child. Having a language is the foundation to learning, well, to everything. We all need language to be successful and happy. The way we get language is through constant exposure to fluent language. Deaf and hard of hearing children usually lack constant and consistent exposure to spoken language. Compared to hearing children, they will have a harder time learning spoken language aurally and orally. Not that it can't be done. This is where sign language, such as ASL, can help provide constant and consistent access to fluent language models.
Now, the two major concerns I have about choosing sign language as a main communication modality (with hearing families) are the availability of good language models and commitment of parents or caregivers to learn and use an entirely new language consistently. The deaf or hard of hearing child will be learning language as his or her family learns a new language. Language will be choppy and inconsistent at first. It would be ideal if the family knew a deaf native signer, because then they can provide a good language model for their child as they work on improving their signing skills.
But, for the single mom, the poor family of 8 or so children who live in a rural area, the dad struggling to learn English or another new spoken language as he adjusts to living in a new country, the parents struggling to keep up with the demands of their jobs, and even the average family dealing with everyday life, it will not be so easy for them to learn a new language and be good language models for their young child. Not everyone is so lucky to have the time and resources to commit full-time to learning a new language while dealing with other ways to help their deaf or hard of hearing child, (choosing schools, hearing aids, whether or not to consider a cochlear implant, how to deal with another existing disability, etc.) and while dealing with everyday life.
The same can be said for aural/oral methods or if one were to choose other ways of providing access to fluent language. Not everyone can afford to send their child to an AV therapist or a good private oral school for the deaf. Families have to be committed to working with their child on learning spoken language and to be more aware of ways to expose their child to spoken language through auditory and oral methods. Again, not everyone has the time, money, or resources to give their child the best environment and models for learning language.
I see this with the families I work with. It is a daunting task to have to swim through enormous amounts of information about ways of helping deaf and hard of hearing children. It does not surprise me when I present the idea of learning ASL to some families that they look at me as if they want to cry. In addition, families will have to choose very soon how they wish to raise their deaf or hard of hearing child (for example, it is not recommended to wait until they are 5 or so to implant them). This has got to be frustrating. I can't even imagine!
It is not so simple. It is not so black and white.
It is very important that families be educated about sign language and all communication options and to have more knowledge of and access to other deaf and hard of hearing individuals and professionals who strictly deal with language learning development of deaf and hard of hearing children. Of course these professionals must have an in depth understanding of all communication modalities, Deaf culture, and sign language. In addition, they must not be biased. But, these types of professionals are extremely rare in many areas of the United States (at least qualified ones).
If I was a hearing parent with absolutely no knowledge of deaf and hard of hearing people and was told that my baby is profoundly deaf, I don't think I would know what to do.
Ay, I am getting a headache just thinking about it!