A while back I commented on my belief that criticism delivered rudely or from a position of smug self-perceived superiority ends up having no constructive value. It's being intellectually nasty and exposes deep insecurity on the part of the "critic". Negative criticism can be delivered in such a way that it has great value to the writer.
I recently posted Chapter 6 of my ongoing series. I received an email from a reader who was upset over the actions/non-actions of the characters, and the sense that another seemingly minor background character was the victim. The criticism was delivered in a way that wasn't a personal attack on me. Even though the reader was clearly quite upset, his/her anger was directed at the characters, not me personally. That enabled me to sit down and contemplate his/her concerns. I quickly came to see he/she was raising some extremely valid issues, things I knew about but hadn't addressed (that comes in part from being an amateur and not really knowing how to manage a full-blown story on all the levels it needs to be managed on).
Now I know I have some issues that need to be addressed. If one person feels the way this reader does, then surely many more do, too. I owe it to them, the story, the characters, and myself to clarify things and confront the issues raised.
What it comes down to is the reader offered some fairly harsh criticism, but it was done in a way that I could extract a great deal of value from it. That kind of criticism needs to be embraced and addressed. It can only make me a better writer, and the story more interesting and (I hope) compelling.