I think you're forgetting an important factor: people want to believe what they want to believe, and most people want to make decisions quickly. So, yes, if they're already leaning towards a practitioner, they will say, "12 positive reviews to 1 negative one, that person clearly just has a problem." And if they're in a hurry, 12 positve reviews looks pretty good - heck, 3 looks pretty good.

Thanks for these. I had seen one before, but not the other two. I don't understand why the person leading the movement is so concerned - I looked at her Yelp! page and she doesn't even have any reviews that I can see. Instead, she has what would drive me away as a potential client - a big ol' disclaimer about reviews.

If you want to write a review of your ex-therapist, who if I remember your story correctly was pretty bad, go ahead. But I don't think it will right any power imbalance, just because of the reactions to online reviews mentioned here - a complaint against her would do so, however. Even if it were dismissed, I believe it would remain part of her licensing file and possibly available to the public (at least in my state).