Regarding my background, I am not a therapist, but rather a reader of many books and a practitioner of self-development for around 35 years who has used (and continues to use) various methods for working through that thing we call Life. With respect to The Work, I have used the technique and still do, for about three years to date, and I began such activities under the care of a licensed psychiatrist during a time in my life when I was experiencing a high degree of mental pain and anguish and required someone other than myself to help me sort things.
Now to the meat of the critique! The lion's share of Mr. Tolboll's article rests on the fact that Katie's method is not original even though she claims it is. I will not enter into the fray of who is original and who is not, except to say that rarely is any idea original. Instead I will offer the counter point of: who cares? Certainly, it matters if for some reason Byron Katie is being deceptive or dishonest and roping people into abusive circumstances. Mr. Tolboll has a point there, if that is his point. However, the method can be separated from the person and looked at in isolation. So, as an unoriginal pre-existing method, The Work can serve as a tool in a toolbox. I think the detractors of The Work need to separate their critiques of the method vs. the person behind it.
When it comes to a method such as The Work, the idea of a tool in a toolbox is important. As the old saying goes, "when all you have is a hammer, everything starts to look like a nail." Mr. Tolboll's points about psychological damage and use of The Work by people with mental illness could hold a lot of merit if those people intend to drop all other therapies or tools for their care. Even in my own care for run-of-the-mill therapy without diagnosed illness, I saw other things along with The Work, such as talk therapy, Robert Keegan's method in Immunity to Change, and other sorts of personal inquiry. The combination of techniques is what produced lasting shifts, and The Work (for me) functions as an excellent maintenance program.
What I want to convey here is that just because a method is bad (in the therapeutic sense) in certain circumstances for certain people, that does not mean it is a poor method in every situation. My claim here is anecdotal with n=1, i.e. just me, but I am putting it out there for those who may benefit from it. If you take care of yourself properly and you get the professional care that you need, I see no reason why supplemental use of The Work is dangerous, and quite the contrary, it can be (and has been for me) helpful.
Having said that, I want to draw attention to a foundational principle in The Work that makes it what it is, and I think Mr. Tolboll misses this completely in his article as he pontificates about the possibilities of practitioners condoning violence, genocide, and abuse while turning it around on themselves. The foundational principle is that The Work only deals with NOW.... not the past, not the future, and not some larger world-wide Now that encompasses all of humanity. No. It deals only with whatever is in the practitioner's awareness, right Now. So if you cannot see it, hear it, taste it, smell it, touch it, etc., it does not exist for you in the present moment. What does exist for you in the present moment, however, are your thoughts as an never-ending stream of babbling in the background and often the foreground too. This is what The Work addresses, and it addresses them by making a person notice that the thoughts are just thoughts, and that without them all that exists is everything else in your perception right now. 99.9% of the time, all that other stuff in your perception right now is just fine and dandy. Waking up to that and enjoying it without worrying about the thoughts that keep kicking you out of the moment is what The Work can accomplish.
This however does not mean that a person's way of dealing with the other 0.01% of the time when the shit really hits the fan will necessarily change. When your Now truly sucks, you deal with it. When someone cuts you off the road and you nearly go into a ditch, you swerve and try to gain control of the car. All of your being is awake to that and working toward it. In that exact moment of freakout, you are not thinking about past or future or how it's really your fault that the accident happened, if it even is. Nope. You are trying to stay alive. For all those times when practitioners of The Work are documented in Katie's books talking about The Holocaust or other horrible events, those events are not Now, and that's the point. You can be stressed about an event that happened 70+ years ago and wind up producing cortisone which will mobilize fats from your cells and begin to clog your arteries, or you can realize that the stress is a thought and that the event you are worried about is not happening right Now, in your perception.
Once again, I am not a therapist, but I will venture to assert that all mental trauma in "normal" people arises from thoughts about things outside of current perception, and the resulting symptoms are due to people stressing over and believing in those thoughts. Existing in the present moment does not mean that you stop thinking and refuse to deal with those thoughts. On the contrary, it means you DEAL with them, right Now. You look at them and study them with respect to the present moment and then see what merit they hold and if they are real or not.
The article by Mr. Tolboll also talks much about the abuses perpetrated at Byron Katie's School for The Work, a 9-day intensive retreat where practitioners work through their issues. Having never attended that event, and not being what Tolboll would classify as a "follower" of Byron Katie, I cannot attest to the accounts he gives. I have no reason to disbelieve them, and they seem disturbing as read. It is good in any sense before getting into a group that you look for and understand the signs of cults and make sure you take care and act cautiously if you see signs. I found it to be a good warning before getting into one of those retreats, but once again, The Work as a method is not the retreats, nor is it Byron Katie, nor is it the only such tool for personal development and care.