I don't think anyone truly hates something they finish. Perhaps you're not 100% satisfied with something, but that is the nature of the beast isn't it? Artist, of any media, are all perfectionists. It would truly be sad if, at the end of a project, you can't congratulate yourself on finishing and take away something positive from the experience. I think that, if you do, then maybe this isn't what makes you happy, you know. Hate is such a strong word, stronger than people give it credit for. Unfulfilled or, maybe, overly critical would probably be a better way to surmise that feeling.
But loosing work is by far the worse thing that can happen. Nothing more frustrating or disheartening than that.