Problem is that 50% of people do not get bad stuff done to them walking down the street.
First of all, that 50% figure is this thing you heard once that said "50% of all marriages end in divorce." Whether that figure is accurate, or even reflects a meaningful statistic, is beside the point, since the divorce rate is not what was being argued. You would have to quote statistics on what percentage of that group that divorces suffered negative consequences from joint bank account ownership. If you find those stats, please feel free to post again.