Sheryl has an opinion, the letter's author has an opinion, I have my own opinion. We are all free to share our opinion. I am weighing in because I care immense

Sheryl has an opinion, the letter's author has an opinion, I have my own opinion. We are all free to share our opinion. I am weighing in because I care immensely about women in tech and feminism and disagree with the point of view portrayed in the letter. Am I not allowed to share my opinion because I haven't read the book she's violently disagreeing with? Just because I haven't read the book doesn't mean I haven't seen Sheryl speak numerous times and don't understand her point.