I am not acting as anyone’s Lawyer here:
Even if, in theory, the spouse would not be held responsible for pre-marital debt, in some places/cases – the effect would be largely the same:
The spouse’s income which goes to service the debt, is lost to the marriage. In addition, any common marital assets can still be attached by creditors to secure repayment. The combined credit score for a possible mortgage must include the spouse if their income is being used to calculate the qualification (not so if the one sole income of the person with clean credit can buy a house).
So while the death/divorce “unfortunate” question is relevant – the effect of premarital debt as a day to day effect on a living marriage is less so… “not responsible” is a misleading phrase.