Very good point. You're right that even if you intend to stay committed 100%, the other person could break that commitment, which would be no fault of your own (similar to a car crash which was not your fault, or a health issue also not caused by your own action).

I suppose my response to this would be to say that a prenup does not protect you from the life-shattering experience of divorce. Regardless of your financial situation, divorce in and of itself is heartbreaking, not only for the ex-spouses but for their kids as well. The possible "financial security" that could come due to signing a prenup does not make up for the emotional and psychological (or even social) devastation that come with divorce.

You hit the nail on the head in saying that broken trust is soul shattering. It is, and "protected" finances won't change that.

We'd all be a lot better off if people truly saw marriage as the lifelong commitment that it was intended to be, and didn't feel this need to plan for divorce, financially or otherwise.