The thing is, "Code of Honor" wasn't actually written with the intention of portraying the Ligonians as African. As scripted, they're based more on feudal Japan, as mentioned above, and the dialogue has lines comparing their culture to Ming China and Native American "counting coup" customs.
Exactly - casting
against type is the thing they attempted here. Sort of the exact opposite of "Up the Long Ladder", and less clear-cut than "Angel One" where flipping the gender left no room for interpretation. A scifi thing to do, and with TOS precedent, but perhaps not all that easy to pull off.
SG-1 got mileage out of casting
in type, even if it sometimes required a bit of blackfacing, considering the global scope of the fictional setting. But SG-1 then got critiqued for failing to get the type right: their Mongols or Egyptians or Early Christians or whatnot were fish-in-a-barrel targets for pointing out errors in detail or in whole, as there was no leeway from the scifi setup. (Or, rather, there was - nobody should have expected Mongols to remain true to form if separated from Mongolia for centuries on an empty, forested planet, yet the critics still did.)
I would have assumed that, just for a change of pace if nothing else, the show would have had a number of episodes that employed a guest cast that was majority, or plurality, black. There could have been a variety of TNG stories that just happened to have a significant number of black actors as guest stars.
True enough. We have come to expect adventures where the majority of the guest cast is blue or green, after all! Going all-black would theoretically have had absolutely nothing to do with African-Americans.
In practice, though... Any episode where this thing didn't just "happen" but in fact had some sort of a story rationale
would have touched on racial strife (even the ones with the blues and the greens generally did!), and there were specific episodes reserved for that.
Besides, alien life supposedly would be diverse. So a diverse guest cast would seem apropros.
Now that is another issue that crops up often enough in these discussions. Busy commerce hubs might be diverse. Primitive farming villages or advanced strongholds of dominant factions might be expected
not to be, though. In "False Profits", say, one certainly wouldn't expect to see a single black face in the white crowd - if not for the fact that the Prophets were there, no doubt attracting travelers from far and wide even on this planet where long distance transportation was primitive or nonexistent. And Bajorans might have settled in their racial niches just like they bowed to their caste system fates - but Cardassians would have been oblivious to that, or exploited that, and there could have been forced relocations galore. Etc.
Timo Saloniemi