The bottom line conclusion, that consensus decision making can be dysfunctional outside of small groups, is correct, but I do fault her for failing to recognize that extent to which some of the other decision making processes are fellow travelers with consensus decision making, but do not actually involve a consensus requirement.
The complex liturgy of consensus process — from the specialized language and roles (“facilitators,” “vibes watchers,” “progressive stack,” and more) to the elaborate hand signals (“up-twinkles,” “down-twinkles,” and the like) — has functioned as much to signal and consolidate a sense of belonging to a certain tradition as it has to move decisions forward.But, many of these specialized features of "Feminist process" aren't necessary consensus based and weren't used in connection with a consensus requirement most of the time when I used them.
The "progressive stack", for example, applies to how discussion was organized. In a progressive stack, people who want to speak are identified so that they don't have to keep their hands raised, but rather than being called upon to speak in chronological order, someone who has said less in the conversation is given priority over someone who has already participated in the conversation a great deal.
The hand signals are nothing more than a "straw vote", used in all sorts of consensus decision making forums (like juries) and in all sorts of non-consensus decision making forums (like political caucuses).
The notion of divorcing the role of a "facilitator" from that of the true group leader, is an idea as old as having a Speaker Pro Temp in the U.S. Senate, which is certainly not a consensus based organization, although Senate rules like those of grassroots groups, often place greater importance on giving everyone a full opportunity to participate than the parallel rules of the U.S. House of Representatives or Robert's Rules of Order.
Feminist process norms that are widely followed in activist groups are more a rejection of Robert's Rules than they are an affirmative endorsement of true consensus based decision making.
Also, even traditional rule based decision making systems that call for votes in the ordinary case, often acknowledge that the process can be speeded up on many matters with "unanimous consent" (another U.S. Senate favorite), with decisions by "acclimation" (used for example, in rare instances, in electing a Pope), and in voice votes, all of which can function as consensus matters. For example, many decisions in political conventions involving thousands of people entitled to speak and vote are made by unanimous consent in practice. The same is true of most votes in most small civic organizations (e.g. churches and family reunions committees).
Of course, one of the main ways of generating consensus is "tradition", something that Quakers and many other small non-governmental organizations have, but that large grass-roots organizations may lack.