Being an editor is a thankless job. (and in my case, also payless. But let's not talk about that at all.)
Let's say you edit a 100 page manuscript. If you catch 99.9% of the errors, someone is going to pick apart the fifteen you missed, and write you a letter about it. (For an example of such a letter, see Pimpboy's acerbic post at the beginning of this thread)
The larger the book, it becomes exponentially harder to edit. A four-page newspaper is going to have errors, and take about six hours to edit. An eight page newspaper... somwhere around four times as hard to edit. I just finished a 16-page paper, and it took me the better part of two weeks. And I'm really good at my job.
I can't even imagine what it would take to put together a multi-media (graphics, pictures, rules format, indexes, and stories, in both standardized and non-linear formats) book like SR4. It runs, what... 350 pages?
Yeah, if someone offered me that job, I would punch them somewhere it would hurt and they would remember it.
-kv