This is a subject that crops up from time to time on blogs and message boards, and usually refers to a discussion on a board that ends with an author saying, "I'm going and I'm never coming back!"
Allow me to say a few words in the defense of authors who get to that point.
Yes, it seems to be a childish reaction, born of frustration and defensiveness. But ask yourself how you felt the last time one of your projects, whether at home or at work, was criticized? How did you feel the last time you were personally attacked -- and believe me, sometimes a bad review can feel very personal.
Now imagine you don't just have to be aware of the criticism, you get to sit in a meeting or a class and hear, in painful details, all the failings. Wouldn't you want to defend your work, to explain the choices you made? So you do, only to find that plenty of people feel you should just sit there, shut up and take it. After all, you put your work "out there." If you can't take the heat, get out of the kitchen.
Easy to say, hard to do. Speaking for myself, I write to be read, or I'd never have sent anything to an editor. I want to know what people think. Okay, let's be real here: I want to hear people loved my book. But I'm well aware this isn't always going to be the case. I can't please all of the people all of the time.
However, there's also a line between what seems reasonable criticism and what seems a personal attack, between somebody saying they had problems with the plot or a character, and implying that you're an idiot, or worse. I've had at least one review that I felt went over that line, and it was very distressing. But even if it's a plot point or something about a character, I can still get pretty upset and defensive. After all, I've labored on that book for months. I've planned, rewritten, revised, edited, lost sleep. It isn't easy hearing somebody say they think all the effort yielded something terrible.
So I absolutely understand the urge to respond to negative comments about a book. I can appreciate what drives authors to comment, and how frustrated they can get as they continue to try to justify their decisions.
But I never respond to reviews or posts on a message boards or Amazon, even to ones I felt were really off the mark about one of my books, for one simple reason: it's pointless. My book is done. Like it or not, it can't be changed. It is what it is. I did my best. And when I see what can happen to authors who do respond? Then it really seems like a mug's game to reply.