Another author has a book with a universally acknowledged boring first chapter, but (says he) it has to be there as an introduction to what comes next. Hmmmm. I suggest that if it remains there then it renders the rest of the book unnecessary, because no living begin will read that far.
But many authors defend their literary anvils, often furiously. Sometimes the authors become quite annoyed with me, before I've had a chance to say a word. I'll just sit there while the author explains the enormous, obvious problem of the book, and then proceeds to argue for it item by item, becoming increasingly annoyed with me for what s/he perceives must be my unspoken thoughts on the matter. (Either that or my eyes speak volumes, and I'm unaware of it.)
I'm not saying that authors should cut, rearrange, re-write or otherwise muck about with their books just to please colleagues, editors and agents. That kind of insecure pandering is dangerous, and it can lead to a bland, groupthink manuscript that speaks to no one. But I do believe that collective wisdom can occasionally be wise, especially when every reader has the same issue in the same place.