I don't get what playing in a good or evil campaign has to do with anything.
Unless you are saying that they don't start in the area, so they don't bother even thinking about it, but in that case why are such DMs so adamant about the vision for their world?
"My world must fit my vision, but since we are starting in Kalay, I'm not going to bother designing or thinking about anything not directly connected to Kalay and the party"
Personally, I wonder if your answer highlights exactly what I'm talking about, since it seems that building the world that the PCs aren't interacting with and may never interact with doesn't seem to even occur to you as what I was discussing.
I would ask that you go back and reread what I wrote. I, no matter how it is interpreted, said the DM does not make those empires. They do. I know I have for my lore. They interact, trade, and have all the culture that a human town has. In fact, they might even be more fleshed out, as they are probably an area of primary conflict for the PC's.
If you are referring to me saying they are recessed, think of recessed from common cultural norms. Hence, why I mentioned slavery as your top four empires.
And I thought it was obvious why I would mention an evil campaign. Because that most likely would be the origin of some of the PC's. Just like if they were elves, I wouldn't start them out in an evil druegar city (well maybe

), I wouldn't start out a bunch of drow PC's in a city that wants to kill them. (Again, provided where going with the common typical FR lore.) This is why I used the word "
focus." Maybe I should have used the word focal when referring to starting a campaign. But, when it comes to world building, all is built.
I find it fascinating that many don't seem to believe or understand or accept that.
My guess is that if one were to ask a DM that has spent a lot of time building their world, that person would receive a metric ton of papers, notebooks, maps, characters, etc. (Especially if printed out of flashdrives!) I don't know. Maybe I am wrong. Maybe I am in the minority. But I know every sentient group on my continent. I know how they interact. I know their religion and its effect on the population. I know the climate. I know the primary forms of communication. I know their culture: their fashion, their language, their rituals, their food, etc. I know who they trade with. I know how their economy is doing. I know their strengths, and their looming problems. I know how educated they are. I know their laws. I know how they settle disputes. I know their natural resources. I know their leaders. I know what their leaders are up to. I know their military might. I know how their military works. I know their primary modes of transportation. I know how safe it is for them.
I say none of that to appear as a braggart. I say it because I am assuming that many many other DM's know these things too. I say it to validify my previous statement that we should give sympathy to a DM that has done all this work and now it needs t be changed because (fill in the blank).