I think any type of therapy can be destabilizing for someone in crisis, and not just acute crisis.

Personally I don't put much stock in different types or modalities of therapy.

I don't think it's the modality that causes the distress, it's the basic nature of the relationship... you have exactly one hour to express everything that plagues you in your life, and then adios. It's too much catharsis in too little time with not enough consideration for what happens after. If you have a problem with that, it's interpreted as evidence of your "disorder". Everything OP said seems relevant to all types of therapy.