In short its about IP. In academia if someone does not contribute enough to the idea itself to be an coauthor then there is no question as to the legitimacy of the grade given to the work. The person who helps you organise your dissertation into a presetable format is not making any intellectual contribution to the work itself.
I used something like a ghostwriter to help quickly publish a research paper. I was called before the chair of my department years ago and called a cheat and a liar. The ghost did appear as lesser co-author as I always intended and had previously agreed.
The response by Dr Howard Curzer a distinguished ethics professor:
This is indeed a complex case. Let's begin with some terminological points. A ghostwriter doesn't appear as an author. (That is what "ghost" means; the ghost is invisible.) Neither does an editor. So if your original arrangement was that this person would do certain tasks in exchange for authorship, then the original plan was that he/she would be neither a ghostwriter nor an editor, but rather a co-author.
If all he/she did was take dictation and change words and syntax, then he/she should not be an author. But the odd thing about your letter is that his/her authorship seems not to be at issue. Rather the dispute seems to be about whether you should be an author. That makes me think that he/she did more than transcription and editing. Or at least he/she thinks so. And since you seem to accept his/her authorship, it seems that you think so too. So one question is: what did he/she do that makes both of you think he/she deserves authorship? Was it like this: You explained the results you got, and he/she wrote it using very different organization, wording, format, etc.? That would be worthy of authorship and much more than editing. But this is just one possibility. Without more information, I am unsure of what to think about his/her authorship.
Let's take up the question of your own authorship. Now the amount of work you did (measured in number of hours) is actually not relevant. Instead, the crucial factor is what your intellectual contribution to the research is. If you were just following the detailed instructions of a supervisor, then you were acting as a technician rather than a researcher. But if you were given general instructions and left to figure out how to accomplish the task, then you were a researcher making an intellectual contribution. Or if the project was your idea in the first place you were obviously a researcher. There are many possible scenarios, and there are borderline cases that add an extra level of complication. Overall, I wouldn't want to take a position on your authorship status without knowing more of the facts. But to repeat, the general principle is that the larger your intellectual contribution is, the more deserving of authorship you are.
Updated comments from Dr. Curzer:
I think I understand the negativity on the page you mention. It arises from the fact that the CHE article is not really about ghostwriting at all. It is about one person paying someone else to write a paper from scratch. The student then presents the paper as his/her own work, even though he/she contributed absolutely nothing to the paper. That is pretty clearly immoral.
You could leave my stuff in the comments, if you like. Or you might take it down since it doesn’t speak to the issue discussed in the CHE. Either way is fine with me.