The book this post is based on (Serious Creativity) is also pretty critical of traditional brainstorming and "withholding judgment." I chose the word "brainstorming" in the title because it's catchier and more connotative than something like "idea generation." Here's an excerpt:

The traditional process of brainstorming sometimes gives the impression that deliberate creativity consists of shooting out a stream of crazy ideas in the hope that one of them might hit a useful target...a scatter-gun approach to creativity makes no more sense than having a thousand monkeys banging away on typewriters in the hope that one of them might produce a Shakespeare play.

He also discusses later in the book the differences between group and individual brainstorming, with the suggestions that, if you want to do a group brainstorming session, it should be split into repeated individual-thinking (separate from each other) followed by discussion, followed by more individual thinking, etc. One problem he identifies with group brainstorming is that you have to slow down a lot to explain things to other people.