I love this argument. It never gets old. ;-)
For what it's worth, everyone says how dangerous Trappy & crew are being, but have there been any incidents? They have flown hundreds of flights, yet no incidents, so if anything, I'd say the experience argues the exact opposite of most people's complaint. While I wouldn't want to see just anyone going out there and doing the same flights, I think they have proven that even in the early stage of this technology, they could be operated without incident in populated areas providing the pilot and gear are up to speed.
Personally, I think we will look back on these discussions one day and laugh that we ever thought this way. Kind of like the argument that automobiles would scare the horses way back when. The technology will catch up soon and provide a solution for flying over crowds. Things like alarms, standard parachutes and airbags will make these aircraft safe and we won't think twice about flying over large groups. We aren't there yet, but those days are coming sooner or later.