[downerending]

In short, the problem is that it's divisive as well as pointless. If I tell you to follow one of the world's "golden rules" (e.g., Treat others as you would wish to be treated.), you will tend to remember that we are all walking through the world carrying our unique burdens, and will perhaps remember that when dealing with your fellow man.

If I provide a list of specific categories, you will tend to think not of the unity of humanity, but of a specific set of historic problems, and tend to rank those you're talking to in terms of those sets. As we're seeing in contemporary culture, this generally makes things worse, not better.