That may have nothing to do with deafness and simply a personal limitation. And I don't mean that in a negative way--just that everyone has their own abilities. Some people are good at cooking, while others aren't. Some are good at music (I have no musical ability whatsoever), while others aren't. Some are better at expressing themselves in writing and others aren't. I happen to have a degree in journalism, and I'm a published author--I know how to write a sentence.
My brother is profoundly deaf, he has a degree in English (almost a second degree in education), and can write with style easily. Just something he's always been able to do. I'm horrible at math--he's not. I'm...okay, I'm trying to think of something I'm good at that he's not...and it's becoming humbling, the little jerk.... ::grumble:: Um... I can name that tune in 3 notes!
Okay, that doesn't count. I'm better at philosophy than he is (mainly because it's less of an interest to him). I AM a better writer than he, but he's not a professional writer.
My point is, everyone has their strengths and weaknesses. I used to write books with someone who writes with his wife under her name. He does the major plot work, and she writes the actual words in the book. He and I worked the same. I now work without him, having learned a lot of how to plot from him, but he can't write prose (other than editorials or letters) to save is soul. He can write as well as anyone--but doesn't have the ability to make interesting prose from nothing. ::shrug:: That's just how it is.