As one of my favorite bloggers, Nathan Bransford pointed out in one of his recent posts, no matter how wonderful you are or how fabulous your book is, someone out there isn't going to like it. I've also heard stories about Judy Blume nearly throwing her typewriter off a cliff (back when writers wrote on typewriters---Judy Blume is classic, ya know.) Someone gave her a bad review and she thought that it wasn't worth going on after that.
Writing, like any art form, feels personal, and there's an expectation that writers take any feedback about their writing personally. If someone in your critique group makes comments about your writing, s/he must not like you. If you're lucky enough to be published and get a review by a reviewer that people actually read, but the reviewer gives your book a negative review, obviously, that person hates you and your ass-face, right? I can't speak for everyone, but I'm comfortable guessing that the answer is probably no.
First, every writer has produced a shitty manuscript. Not all of Shakespeare's plays are all that. I mean, seriously, who has read The Merchant of Venice without having it forced on them? D.H. Lawrence's Lady Chatterly's Lover is a joke. Also, even writing a good book doesn't guarantee people will read your book in the future. The majority of books go out of print fairly quickly and the ones that stick around run the risk of the Catholic-Bible treatment Huckleberry Finn has suffered through. Anyway, as a writer, you either write bad stuff once in a while, and you know it, or you write bad stuff and you just aren't ready to face it yet. It's okay. The denial lifts with time.
Second, critique groups and books on how to write books have lots of rules about what makes a good book and what makes your work publishable. For example, make the first three chapters really exciting because if you don't, your reader will give up and pick something else. Don't waste those precious first pages with set-up! Um, has anyone heard of a little book called The Girl with the Dragon Tattoo? If you've read it, you know that it doesn't really get interesting until around page 48. Is that an example to follow? I don't think so. I don't care for the way it starts, but my point is, the book got published, and people like it. If you have a good story and you tell it well, that's what readers care about. They don't care about whether or not you've read Story by Robert McKee. Most of your readers are joyfully oblivious to that book. They don't want a formula. They don't want someone who got published for good behavior. They want to be entertained. If formulas and tips help you do your thing, that's great! Just don't let them bog you down.
As for feedback, all feedback is a gift. We make creative work for a reaction, at least, I do. Some people react positively. Some people react negatively, and it's all interesting information about the work.