No one likes criticism. Especially when it's directed at something they've worked long and hard on.
But criticism is essential for finding errors and oversights. So the question becomes: how to accept criticism and distinguish the good from the bad.
First and most important, make sure the criticism comes from a trusted source. A random review on Amazon shouldn't hold as much weight as an editor's comments or a critique partner's suggestions.
Personally, when I send out my draft to beta readers or my editor, I like to receive the initial criticism through email or as comments within the document. That gives me time to go through it and get past my original emotional reaction. Once I've gotten past the instinctive stage of "But that's not what I meant!" then I can settle down and start figuring out which issues I agree with and which I don't. The fact that I can do that in private helps me to maintain a professional manner. In person, it's too easy to slip into being defensive.
With my first novel, the developmental edit had 30 pages of notes as well as over 400 individual comments within the manuscript. That's a lot of material to go through and while I agreed with a great deal of it (after some thought), there was also a large amount which I didn't agree with and some where I had a hard time understanding what was being identified as a problem.
I sat down with another author and complained. Here I'd spent all this money and it looked like they hadn't read the draft carefully. After all, they were saying I hadn't explained certain things but I had. That's when I received some of the best advice I've ever gotten about criticism: Forget the details and focus on the gist.
In other words, there is usually some truth at the root of all criticism. If they say the relationship between the hero and heroine seems artificial and false, then that doesn't necessarily mean it's unsalvageable. It may mean that some more depth needs to be added to the characters' point of view, showing us the internal emotions. The problem may not be with the relationship but with the way the characters are shown.
Finding where the actual problem is can be a challenge and sometimes it takes multiple perspectives to figure it out. If one criticism complains that the plot feels rushed, another that the ending feels unsatisfying and another that readers are lost trying to figure out what's going on, then those all point to pacing problems.
It's not easy to find the answers and in the end, I believe an author needs to respect his or her own instincts, even if it disagrees with the critique. But it's also important not to dismiss anything out of hand. Ignoring any suggestion or concern needs to be a deliberate and conscious decision.
Criticism is difficult but necessary, like rough sandpaper which polishes stone or wood into a glossy shine. It may be abrasive, but your story won't gleam without it.