Maybe he was just going for WotC settings, Arcady? in which case RL could count, because it _was_ published by WotC, but Kalamar would not. But if that's the case, he's missing Dragonlance, Dark Sun, SpellJammer, Planescape, Brightright, Mystara, and probably another one or two I'm forgetting in sleep-needing haze.
"Oriental Adventures" isn't a campagin setting, either.
I use a homebrew world and Loerem about 50/50, depends on the moods of me and my players. On our off time we play in good old Dragonlance normaly, as we have a lot of DL fans in my group.