One extravert felt the book painted them as boors and made them feel guilty. Some felt the psychology was a bit simplistic or the anecdotes detracted from the integrity of the other research. Not everyone had finished (myself included).
You could tell the book had struck a nerve.
Cain observes that North America is built and designed for extroverts, yet at least 1 in 3 is an introvert. Workplaces, classrooms, and organizations encourage extroverts in open design, group work, brainstorming. The point of the book really is to recognize the power of introverts and introspection, and build systems and structures that respect that dimension of society.
Some quotes that stood out for me:
"Introverts living in the Extrovert Ideal are like women in a man's world, discounted because of a trait that goes to the core of who they are. Extroversion is an enormously appealing personality style, but we've turned it into an oppressive standard to which most of us feel we must conform."
“...if you can think of meetings you've attended, you can probably recall a time - plenty of times - when the opinion of the most dynamic or talkative person prevailed to the detriment of all.”
I had the pleasure of watching Cain present at a conference. Poised and thoughtful, she did a great job. Since then I've seen the Ted Talk and the Googleplex videos and they are so similar, you can tell Cain had to do painstaking work to get stage-ready. She confesses the seven years to write the book was bliss, but the year spent promoting it was her "Year of Speaking Dangerously." The skills needed to write and market are very different but each essential.