It's simple. It's worth advocating, but it's cruel. Many times it is used by people with ulterior motives to persuade people, and people who persuade people often have ulterior motives. Every time this happens in history, it's disgusting. In other words, it is a noble spirit to voluntarily "give up the small family for everyone", but few people do it, and most people don't want to do it at all. It is not a happy thing to let others sacrifice for themselves in the hearts of people with conscience. It is a dirty thing to say "give up your family for everyone", which is dirty from the inside out.