In my experience, people who are heavily critical of it have not read the book, and are arguing either against articles espousing it, or have encountered what I call "The cult of NVC" at work.
The NVC book is incredibly simple. But there is a sort of cult around it. People greatly expand what's in the book to things the author never claimed. I've even attended an NVC chapter in my city and it was somewhat off putting.
If you're at all interested, read the book and avoid the cult. It's not a perfect book/framework, but I've yet to read a better framework. The downside of the book is it's relatively prescriptive, and doesn't cite research, or do a good job of explaining why the method often works. Other books do that, though. Had I read NVC by itself, I too would be a bit of a skeptic. It's only by reading other books that go deeper did I understand why NVC (usually) works.
