In fairness, VWP travel to the US in circumstances that mean you might be considered to be working there has not been a good idea under any administration. If you're a professional tattoo artist and you arrive for a month with tattoo equipment and the stated intent of "making art" during that time, it's pretty clear what you're going to be doing.

What is concerning here, as an occasional bona fide business visitor to the US, is that it was always my expectation that if I were refused for some reason then I would just find myself turned around and placed on the next flight back. Seeing someone held in a private, for-profit, detention centre for an extended time period is not the behaviour I had previously expected from the US. It is a worry.