The reason that this is relevant is because of the special place of Gallaudet University in the deaf community and because of the idea that it is important for that community to be in control of its own destiny.
The deaf community in the United States feels that it has its own distinctive culture and its own issues that only another deaf person can understand. It feels that deaf people have been treated as handicapped people by hearing people for too long. It feels that deaf people should be in control of their own institutions (the most visible of which is Gallaudet) instead of having outsiders come in and tell them what to do.
You could draw an analogy to a country that has been colonized. The people of that country, once it becomes free, would not like to have people from the colonizing country come to rule them. They would like, instead, to control their own lives. This is why deaf people want to have a deaf president for Gallaudet University.