How about the show spends time on human characters who really do come from a variety of backgrounds and real, existing human cultures? Trek gives a lot of lip service to showing people in the future overcoming their different beliefs, prejudices and misunderstandings to live and work in cooperative and productive ways, but it almost never shows any of that: just a lot of Americans and Brits speaking with funny accents and all behaving very, very much like middle class Americans. Oh, and some actors with stuff glued on their faces.