One reason some people–and many countries–insist that all persons have an intrinsic and equal worth is that the alternative view opens the door to dehumanization, and, ultimately, to genocide and other atrocities.

In addition to this, many people recognize that it is not their place to judge the innate worth of another person. It's not their job, nor is it within their capacity, and they are not required in their daily lives to make real world decisions about the innate worth of other people. So they don't entertain the question, because it is an irrelevant question that they can't answer anyway. Some believe only their creator has the necessary authority, knowledge, insight and the power to make other concerns irrelevant.

This is true of the lives of pretty much all human beings on this planet. Nevertheless, many still take it upon themselves to judge the innate worth of other persons, engaging in such exercises even though there's no need. I presume some get a perverse pleasure out of such dehumanization.