This is definitely your father's issue. But, to answer your question, parents can and do feel disappointment in their children. It's normal. BUT, if the child is just being who he is, (barring drugs, crime, etc.) there is never, ever a reason to express to the child. I can understand a parent being disappointed about a special needs child, however, it seems to be about the parent's feelings and inconvenience rather than the child's life.
And comparing children to each other is never, ever good.

I'm glad you love your brother so much. You can't change your father's behavior, so just try to be there for your brother.