What started as an entertaining stage show soon got a bit raunchy in the views of some of the student audience. A college is a diverse place, and I'm sure a lot of the people watching thoroughly enjoyed it. I've definitely been to an adult-themed hypnosis show, but I and everyone else there was expecting it - the marketing material proudly proclaimed it to be X-rated, though it might have squeaked by with a PG-13 if it were a movie.
When you perform a show in front of a mixed audience, it's fairly important to perform to the lowest common denominator of tolerance to offensiveness. The story doesn't state if the marketing materials had proclaimed it to be on the wild side, but I imagine if they had, those who would be bothered by it wouldn't have shown up in the first place.
But the difficulties in playing to your audience extend beyond even that. The hypnotist, who is unnamed in the article, is described in the articles thusly: "a very bulky man with a long pony tail, arrived on stage wearing all black clothes and a pair of strikingly white sneakers." Not the best of appearances for garnering trust and acceptance, but probably thought to look edgy and attention-getting by him. This issue extends even into a private practice, where wearing serious clothing will get people to take you seriously.
Did all the subjects volunteering know what they were getting in to? Probably not, but if they were truly bothered by it, they wouldn't have stayed on stage very long. But, given that my friend once described a similar show as "mental rape of the feeble-minded" it's clear that the audience doesn't always know or care if that's the case.
One screwup like this can seriously hurt or kill a career as a performer, and can certainly result in one less venue to play. If you can take the lessons and apply them to your own hypnosis sessions, you might avoid a similar fate for your endeavours.