I've edited a lot of different writers of widely varying skill, and I've come to associate two things with a particular subset of beginning writers. The first thing is a refusal to address point-of-view problems, and the second is a tendency to talk about their "voice".
Writers who exhibit these two traits rarely manage to improve their writing past their current level. I've come to believe that the two things are related. I think that for some reason, these people have come to believe that they are now "good" writers and don't have anything else to learn. After all, Nora Roberts switches POV all the time they say in their own defense. Yes, but they aren't Nora Roberts, are they?
But the real problem is that they lack the sensitivity to tell the DIFFERENCE between a scene in which the writer switches POV character at whim and a scene that stays tightly bound to one character's point of view.
Writers who haven't reached their greatest level of competence recognize when a correction or a suggestion is right. Their sensitivity is greater than their ability to write, which means they still have growing room. They have the ability to improve. Writers who reject corrections and suggestions because they don't believe them, because they can't perceive the problems, have no room to grow. They've reached their level of incompetence.
Without the ability to perceive--or accept--a weakness in their writing they are dead in the water.
So the next time you have the urge to prattle on about your "voice" to an editor, you might want to consider whether you are marking yourself as someone at a dead-end, someone that is going to be difficult to work with, someone who has finished growing as a writer.
Of course if you are a hobby writer and happy with that status, go for it. Hang on to your precious words for all you're worth. I certainly don't want them.