This is an extraordinary piece, and many of the quotes from this book are tremendous. Somehow I had never read it.

It is shocking how so many replies are hostile or defensive. The author (or the author the author is citing) isn't even claiming that movements are bad, or giving any qualitative judgment (e.g. citations about equal rights or the American revolution as if they're counterpoints somehow seem off the mark), just noting the qualities of most movements and the environments in which they occur. If you're looking to engineer a group for some cause, even if the cause is ostensibly good, this is a good how to guide.