While the Goenka retreats profess to be secular and for everyone, I got serious cult vibes from the minute that I arrived. Technically, the in-person instructors are only assistant teachers. There is only one true teacher: Goenka himself. During his nightly instruction via VHS tape - the only human interaction you're allowed all day - Goenka teaches Buddhist metaphysics (I recall something about vibrations of the universe).
The retreat creates the perfect environment to break you down psychologically: sleep deprivation, food restriction, lack of human interaction, prohibitions on reading, writing, and exercising. Throughout the retreat, there is ingroup/outgroup pressure: only the strong can make it through; people who leave or aren't able to handle the meditation are weak. If you have a concern about your experience, the standard solution is more meditation. If you question this, you didn't give the retreat a chance, you weren't meditating hard enough. Then, at the end of the retreat you're hit with a love bomb on the way out the door. [1]
Interpreted charitably, I thought this retreat was similar to military training or fraternity hazing. Less so, it was more like solitary confinement or torture.
I'm glad I went - I gained some insights and it was an incredibly valuable experience. I'm also glad I left early. If you're thinking of going on one of these retreats, know what the assistant teacher told me on mine: "This is a Buddhist purification ritual."