If you are like me, you can take criticism well and grow from it because we find it nice to have another mind to help catch mistakes. If you do not, well I can give you a couple reasons why you should value another persons criticism. Let me be clear about one thing. If someone comments on your work with “That sucks.” or “This is the worst thing I have ever seen.” you are dealing with an asshole, plain and simple. Criticism is telling you where exactly you went wrong and/or offering suggestions to amend mistakes in a positive and encouraging manner. Never listen to anyone degrade your work or you as an artist, they clearly have poor taste if the only thing they have to say is negative and rude in all respects.
Critiquing is a great tool to help you improve in your writing because the insight of another persons mind can give you a little perspective. For example, you might really like the angle of your story but another person might read it and interpret it differently. It happens a lot with setting imagery, but it also occurs with character descriptions and plot direction as well. After reading Game of Thrones all the way through, I can honestly say the terrain in my mind matched really well with what HBO producers had in mind with the TV series, but a few of the characters were slightly different than I imagined- excluding the obvious fluke with HBO’s impression of Daario Naharis. That aside, it is difficult to get what you envision to fit the same image in your readers minds, but opinions from beta readers, friends or family might help you see what they see and then it is for you to decide if you need to change things up, expand upon an idea or shut it down.
Criticism is also useful for the more mechanical side of writing. Do you ever get that bogged down feeling after a couple hours of writing? Sometimes it is lack of inspiration or distraction, but I go through times when I cannot get what I want out on paper even though I know exactly how the scene is to play out because I can see it vividly in my mind. I experience a problem that is more troubling than inspiration or motivation; it is my own dissatisfaction. No, I am not diagnosed with anything, but I have my perfectionist moments where I want it to be exactly as I imagined it or I do not want it at all. It is frustrating beyond belief, but I will put the pen down or walk away from the computer when I can’t get something right after awhile. More specifically, I drive myself crazy with repetition, the lack of how to say the same thing differently. Overuse of the same words or phrases irritate me to no end. Though, not long ago, I was reading a critique on another piece of work and they were telling the author to try writing through the block, even if it meant it would need some serious editing. They expressed the importance of getting your ideas out and onto paper above all else. It was a great suggestion.
As an attempt to resolve this personal issue, I have started taking that advice and thus far it has helped a bit. Instead of completely giving up on what I am working on, I will write the scene down in a different format and highlight the whole paragraph to go back and edit later. Instead of third-person, past-tense- which is my preferred perspective to write in- I will jot my ideas down in first-person as if I am telling personal account of something I witnessed. Storytelling is so much easier for me than trying to perfect all the little details because it highlights the major points and ensures that I won’t lose the idea while I take time off to refresh myself. Sometimes a new pair of eyes will catch things you will not always see, and so long as your works are copyrighted or protected in some way, you should not fear sharing them. I recommend doing your research on copyright before sharing any writing that you may wish to publish. In the event you enjoy free-writing for practice or fun (with no intention of publishing or selling) and want critiques on style, plot progression or character development then I suggest you try a writing contest/forum or ask a friend to take a look. In case you were not aware, many universities have a writing help desk that will look over your papers and go through your work with you for the sake of improving writing skills.
Do not be afraid of constructive criticism, use it as a tool to grow as a writer!