i think one of the reasons they may have failed is because the setup of the event is so formal. The event begins with a long lecture, and (based off the image I saw before) the rooms they are displayed in are very white and blank, like the inside of a museum. Their audience is also very selective, with mostly artists, writers, art curators, etc, who are used to thinking of art as something precious / intellectual. I think the authors made a mistake in this audience and this design. By making it an exclusive, private event, you also have an audience who is more afraid of interaction.
I don't think ordinary people are reluctant to touch / interact at all. One of the authors shows at the beginning of the article that people at museums who witness the touch tours want to touch as well, especially children. A few years ago i also went to a gallery thing in seaport where anyone who walked in was encouraged to draw on the walls. this is different from the touch tour described here, but it had the same theme of physical interaction with an artwork. because the gallery was open to the public, it ended up being really successful and fun.