"Eeew, what even is that? Can't you see that the face construction is all wrong? And what does it mean, 'I only drew the first four lines, at least let me finish'? Erase it all and restart from scratch!"
"Your drawings are too creepy. They're never gonna sell."
"You do realize that if you present your work like that no editor is ever going to take you in consideration, right?"
"Oh, that's cool! ...But see, the eyes are not symmetrical. The mouth is wrong. The jaw looks weird. You know what? On a second thought, it sucks."
"Why are you sketching that? What does it mean 'it helps you figure out the anatomy better'? Can't you just... DRAW?"
"Artists should never, EVER use any reference. You should be able to draw everything from memory without ever looking at a reference. If you can't do that, just give up."
...All of these came from my illustration teacher. She'd constantly tell me how much my drawings sucked and how I would never get a job as an artist if I kept drawing like that. Fun fact: that very same year, one of my drawings was selected as the official mascot of a very important cruise line. Buuuuut... my illustration teacher "somehow" managed to cut all contacts with said company, thus preventing me from getting the job. Needless to say, I was devastated. Took me nearly 8 years to gain any confidence in my art again.
I'm all for constructive criticism of my art, but being told that my drawings "suck" and that I should "restart from scratch" when I haven't even finished the base sketch and I'm not even being told what is wrong with my drawing isn't exactly what I'd call "constructive criticism"