Insurance.
I have to think that, at some point in this venture, insurance is going to have to be gotten for the spacecraft, the lives and health of the people involved - both the organizers and direct participants, insurance for contractors' (and astronaut-trainees') performance or non-performance, liability insurance, insurance for the advertisers who will buy time in advance that will help fund the venture, and more kinds things than I could possibly even think of. And if the insurance can't be gotten, then the entire project will not get off the ground. (See what I did there?)
And I can't see how anyone is going to risk it.
And there is also the question of what kind of government permits they will need (if any) and from what governments? And mightn't a company that gets involved with a stunt like this risk damaging their reputation as a serious space enterprise to such a degree that they will become a sort of pariah amongst space companies? Really, these people are being sent off to live on Mars and at the end of such a tenuous and fragile supply-chain, that the chance of them dying is almost a certainty - and those deaths might be kind of gruesome.
I can't really take the story seriously. Even if project is being seriously considered, the chances of it being realized are very, very remote.