Nor can it build security for the children born in such a relationship. Commitment is hard work. When you find a person who honors a commitment even when times get tough, it says a lot about their character. You don't have to be a religious person to appreciate the value of those qualities. I wouldn't go as far as to say that moral weakness in a person makes him or her incapable of handling other responsibilities, because that simply isn't true.
Most people are able to separate their private and work lives.
Flinn is still perfectly capable of flying a B-52. Ralston is still capable of leading his troops. Whom a person sleeps with is a really nobody else's business. But it does have hurtful consequences. It hurts someone, even if that someone is merely the man or woman who is unable to meet his or her eyes in a mirror.