‎"...suppose a married woman has an affair. Much moral criticism is usually directed at her for having the affair, yet almost none is directed at her earlier self for marrying her husband in the first place. But both of their acts were needed together to cause the broken promise."
...
"We understand the value of being able to credibly make commitments. Promise breaking reduces trust in general and makes it harder for us to work together for common goals.

Of course both the promise and the violation are required for that harm. As a result I think people would think less of someone who made promises they couldn't expect to keep, or which gratuitously harmed their future selves. But in 'far mode' we usually like the promises and don't like the violation, so as bystanders our sympathies usually lie with the person who makes the commitment.

Finally, we have to seem like we value promises otherwise we will not seem trustworthy, so we exaggerate how immoral we think it is to break promises."