I went because I am interested in the similarities between hypnotherapy and meditation. I felt that some of the activity was very similar to guided self-hypnosis, but less reflective (for instance about the subconscious content which comes into the mind when you clear it). I suspect that the outreach programme has taken a fully complex and grounded Buddhist theory and simplified it so that it can be propagated easily by a big staff of volunteer workshop leaders.
The workshop was organised by Nagarjuna Kadampa, who are a bit controversial. They are Tibetan in origin, but from a different lineage tradition than the Dalai Lama. So you never know whether criticism of them is inspired by inter-lineage rivalries, which mean zero to me. I couldn't care less about things like that and I'm certainly not ever going to join anything.
I didn't get the impression they were a cult, but I felt that their core members who were there to support the event seemed slightly weak characters, who had found refuge in a fairly all-embracing movement. Having said that, they had not been pressured as far as I could tell to give up jobs, cut relationships with family and friends, and so on. A man I met who lived in the monastic centre seemed to be slightly educationally subnormal, but he was treated with respect and worked their as a gardener, and seemed to be fulfilled.
So all in all, I am ambivalent about it.