I've read a bunch of therapy forums. Many many horror stories, but they are often masked by attributing the misery to something else, or by equating therapy with other relationships, or by just rationalizing it as part of the "work". It's obviously not all that way, but enough to call it significant, in my observation.

As for whether this place is representative, nobody knows. To assume not is selection bias. I think therapy forums are the only unfiltered, real way to see the effects of therapy, and thus ought to be studied by people interested in such things... of which there seem to be very few.