Deafness is just another disability, right? A disability is just a wide term for any type of problem that sets someone apart from the masses. Everybody has their faults--stage fright, fear of deep water, relationship commitment issues, etc.--but disabilities limit essential faculties. By definition, they imply that the disabled are capable of less.
Of course, deaf people, like all disabled people, are able to live and work just as other people do, but that doesn't mean that they can live and work exactly like them. With certain help, though, they get by.
Here is where things start to branch out and instead of seeing the disabled as a single, large, unfortunate group, you start to see real individuals with actual problems, dreams, ambitions, loves, and much more.