I've had feedback on my novel, which was good and also feedback that seemed harsh. Some of it was completely unjustified, but some comments may have raised valuable points. They totally contradicted the writing tutor's advice before I published, and my beta reader of course. I hadn't published without getting feedback from successful fiction writers. So it really does go to show how subjective it is. It's quite possible they're all right.

I wrote about it here: https://medium.com/writers-blokke/dont-let-the-negative-ninnies-get-you-down-b53c086d8c2b