I think wealth that is accumulated through one’s personal achievements and endeavour (or self-perception of the same) makes people believe their own publicity to an unhealthy extent and leads them to think they are (to some extent) invincible.
I think the wealthy passengers on this trip, accompanied as they were/are by the CEO of the boat-owning company, must have assumed it was perfectly safe. That, the amount they paid (which will have served to reassure them), and that unconscious sense of invincibility would have conspired to dissipate any doubts they may have harboured.
It’s not entirely analogous, but to some extent, we all take a leap of faith, albeit a regulated one, when we step into a taxi or a bus.
Assessment of risk can get severely compromised by hubris and, crucially, the end product of the risk you are undertaking to get there. I took bigger risks than I normally would when travelling to Istanbul, because there was a CL final that I had a ticket for at the other end. Those risks could have turned out to be reckless in hindsight, but I took them nonetheless. It was a calculated risk, but one that could have gone wrong.
These people will have gone through the same thought process, albeit with a tragic outcome. The allure of seeing the Titanic, plus their sense of invincibility because of the trajectory of their lives, and the reassuringly expensive price they paid to embark on this undertaking, all combined to make them lose any sense of judgement about the risk they were taking, which objectively speaking, and with the benefit of hindsight, now seems utterly reckless, but plenty of others have done the same trip and will have thought the risk (which must have been broadly the same) was completely worthwhile.
As much as we try to kid ourselves, and the ultra-wealthy will do this more than most, we aren’t really in control. We are all one throw of the dice from our life turning on its head, as I’m sure all of these poor souls, assuming they are still alive, now fully appreciate, if they did not when they got into the manifestation of hell in which they are now reposed.