I fail to see how Outworld Marketplace does not suit the theme of Outworld. Remember MK Deception konquest mode? There are cities in Outworld in which more or less peaceful life is possible, for instance, the walled city of Lei Chen - until the overlord of the city got into a conflict with Shao Kahn, it was a peaceful city resembling the Earthrealm village.
I am really glad NRS is showing this side of the dark and evil realm we know, but at the same time, I do have a theory - I believe that Outworld got a new ruler who is not a tyrant like Shao Kahn, thus the whole realm looks less menacing.