There is a simple test to decide whether deafness is "just a difference", and whether causing people to not become sign language natives is good or bad. That test is to consider the reverse of corrective surgeries. How many people would undergo it or would apply it to their children? The count so far is zero, so eliminating deafness is unequivocally good, and "surgeries aren't bad in themselves, but they're bad insofar ..." argument is illogical and dishonest.

This is an important thing to understand, because this is the first of the series of discussions we are going to have as we learn to modify more and more things about ourselves. From things like colorblindness, to things that are currently considered as variation of the norm, to radical changes to the brain that would make people undergoing it effectively a different species.

In all cases the criterion should be everyone making decisions for themselves and for their own children, not trying to shame others into staying with your group, or banning others from creating children with or without features you want.