This is a case where regulation KILLED.
Basically this a was thing that was essentially marketed to wealthy tourists. It WAS done under a regulatory environment, and so those people had far more trust in it than they should have. I bet had they been forced to drag the thing out to international waters and do some sketchy bitcoin transaction to pay or whatever they would not have found takers!
Regulation of this kind of stuff simply does not work. What regulator has any experience inspecting a deep sea sub? - None.. What engineer could draft what appropriate safety standards are for something like this? - None at least not without completely stifling innovation.
Yes we know from the post incident analysis corners were cut compromised materials were used and engineers and officers on the project should have know better, but that is negligence and it is why we have torts.
Modern rail roading is a good example, we have a lot of regulation. Mostly it works, but there are still the occasional accidents. Pretty much every rule in the book has one or more corpses behind it, it isn't like someone say down and just wrote out the FRA's inspection schedule, we learned the hard way the inspection frequencies required to catch certain problems before they turn into dead bodies -> then -> we said ok everybody is going to do that.
Honestly the DOT (US or CANs) should have exactly one regulation covering something like this, something akin a product safety label that says, "the safety of traveling aboard a device of this class is not well understood, proceed at your peril"