I also think a lot of people use published settings like I do, I will use the maps, the locations, npc'd, and lore when I remember them but will change and ignore stull and import locations and stuff from other setting as I feel the need. Official lore and contunity means nothing. It is a starting point for me and I only remember half of it at any time anyway.
it is effectively a derived homebrew.
That's a great point.
I wonder how people answered the survey (as well as what the numbers are now). Look, I know that everyone likes to fight classifications, but there are some fine lines worth discussing. Here are a few!
1. I almost always run Greyhawk. But the Greyhawk I run is effectively a homebrew at this point, given that I have "filled in" and changed a great deal of it over time. So, am I running a Greyhawk setting (I think I am!) or am I running a homebrew that happens to use the GH map and snippets of lore? For that matter, is there a difference or distinction?
2. There are a lot of groups that just don't care about settings. They run APs. And this has always been the case. Back in the day, a lot of tables would just go from module to module. Did that mean that they were in Greyhawk? But what if they went from AD&D modules to the B/X line of modules and back again? Were they transporting between the Known World and Greyhawk? Or is that a completely stupid question ... yeah, it is. They didn't care. Same today. If a table is just running through an AP, do they really care about the setting that much?
With that in mind, I do think that there are a lot of tables that choose to create their own homebrew world. Both because there is a rich history of doing so that gets passed down, and also because people see them youtockers and ticktubers playing in their own homebrew. I mean, I will credit Critical Role et al for that!