I write a little and that was one thing I used to be very sensitive about. "It's alright, but I think you shouldn't write this, you should write X" was a mild comment that gave me concern for years! Got a bit of a tougher skin now. A bit.
I got a couple of comments like that (plus some REALLY mean ones, that ridiculed me personally) in the past. One time somebody sent me an e-mail lavishing me with praise and I felt so good, I replied to thank them. They wrote back and basically said, "You're such a talented writer, why do you waste your skills writing all this fantasy crap? Why don't you really make use of your talent to write realistic fiction...?"
So...that was really a slap in the face, right after I'd felt so flattered, too. :/ I've gotten similar advice here on SAS, to write more realistic stuff based on my personal experiences and maybe I'd get readers, but 1. I write to get away from my miserable reality, I really do not want to write stories about it!; and 2. I do not believe there would be any reader interest in my life...I used to blog on other sites and nobody read that, either. I don't do much of anything IRL worth writing about.
I also once had someone gush enthusiastically over one story of mine, then the next story I posted, they simply wrote, "There is nothing about this that is even remotely good." (Granted, I hadn't enjoyed writing that particular story so it probably did suck, but it was a subject that was really popular, so I'd thought it might get more readers. So that's what happened when I tried writing what I thought others would prefer to read, instead of what I wanted to write.)
But mostly I would just get people trolling me over my work. Calling me and my characters mentally challenged, making jokes about Britney Spears loving my "high literature"-type writing, "This story is the literary equivalent of diaper wipings!", telling me to stop writing completely because they'd completely misinterpreted the summary of a story and hadn't actually read any if it at all, etc. A bunch of people made fun of one story behind my back (I found out because the forum link appeared in that story's list of referrals), making a bunch of assumptions about stuff that wasn't even in the story. All they'd read was the story description.
And if I ever tried to protest I was told to toughen up because "a real editor won't be so kind to you." (Even though I gave up thoughts of getting published long ago.) The frustrating thing is one of these guys did make some good points about what needed work, but he was so sarcastic and offensive about it that it took years for me to get his point. I would've gotten it a lot faster if he'd been tactful and sincere.
That particular "reviewer" also ended up kind of stalking me for a while, every time I opened up comments on my site after turning them off, he'd start trolling me again, it wasn't even about my writing anymore.
(I also had one guy, after we had a falling out, repeatedly target my writing as a way to hurt me; he'd sign up with numerous accounts and repeatedly downvote it. Kept at it for a year. I had to restrict my writing from public view. Now every time I get a rating/review on that site, I expect it to be one star.) (All the infrequent comments I get there BTW are just vague "form reviews" from members of review groups trying to get credit. "You used good description here, you drew the reader in here, etc."-type of stuff; none of it is ever story specific. The last such review I got was on my fiction folder, not a story itself...weird.)
I used to actively seek constructive criticism on my work but almost all the critique I got was really sarcastic and insulting and seemed designed to discourage me from writing altogether, so I stopped advertising myself or participating on writing forums. (I didn't even share my work on those, but got lots of sneering criticism anyway, they never considered me a "real" writer so I stopped calling myself one; I've been writing for over thirty years but call myself an amateur or wannabe writer, now. I don't want to mislead anyone into thinking I'm legit.)
I stopped offering critique on other amateur writers' work too (I'd look for subject matter similar to mine), because even though I went out of my way to be polite and helpful (unlike the critique I got), other writers always seemed grumpy about my comments, like they'd tell me, "I KNOW about all the grammar errors, I'll fix them later, why don't you just focus on the story?" (I figured it's best to try to fix that stuff before asking for critique, but I guess I'm in the minority.) I was never rude in my criticism, even with the worst writing I'd try to point out what was good. Plus I'd often spend hours writing up my reviews, and to have all that time and work dismissed so brusquely (if the other writer even acknowledged my help at all, some would publicly thank everyone who'd helped but my name would be left off the list) just turned me off from trying to help out my fellow amateur writers. And they were never interested in helping me out in return (if they did, they'd offer a bland, one-paragraph comment on the shortest story of mine they could find), so...
I figure they don't want my help.
And my experiences with writing teachers IRL, in late high school/college, were just about as bad. I was a wordy genre writer, not a terse literary writer, and so those teachers rarely had an encouraging word for me. (I could devote a whole other post to those bad experiences.) Only the teachers I had in my freshman year and earlier, when I was a kid, seemed to like my work. As an adult writer, I've never been taken seriously. So I guess that means my writing is juvenile.
By now I've gotten so much criticism and mockery I don't want people reading my work anymore unless they want to and they like it. I always assume the default is that people don't like it so I'd rather not hear from them, since I've heard most of the negative stuff already. If I plug my own work, I'm just asking for more ridicule.
...Anyway, yeah. :/ I never stopped writing or thinking about writing or even sharing it, I just don't advertise myself or ask for critique or offer any anymore, or post on writing sites, or try to just socialize with other writers, because I tried all that for years and all I ever got was discouragement and insults. Most of the times I got positive comments were when someone accidentally came across my work or, unfortunately, years after I'd given up hope/lost interest in a particular story. It almost never goes well when I deliberately draw attention to my work, so of course the feedback I get is very rare. Probably for the best, but still.