Even when someone died on the journey, if they'd made it halfway or more, their family members on the ship were sometimes still held responsible for the cost of their trip!
If you buy two cruise tickets with your credit card and your partner dies halfway through the trip, you still owe your bank the cost of two cruise tickets. (That is, unless the right kind of coverage is included in your annual fee.)
The only thing that has changed between then and now is that you might be able to sue for damages if unsafe conditions on the ship can be shown to have caused your partner's untimely demise.
On the other hand, if your partner buys their own ticket, their estate is responsible for the ticket and if it doesn't have sufficient assets their credit card company can go eat a brick.
This is a more reasonable comparison in our modern context where such a contract would be entered into individually, not on behalf of a partner.
The only thing that has changed between then and now is that you might be able to sue for damages if unsafe conditions on the ship can be shown to have caused your partner's untimely demise.