It feels like a lot of interesting campagin settings have restrictions or cultural expectations - maybe based on real world historical, maybe one based on a literary setting, maybe one set in a country based on a particular non-European culture, maybe one based around dungeon crawls, maybe a world without active gods. I don't want those settings to not happen just because there'll always be that one player who, after agreeing to the idea, then wants to be the only dragonborn in real medieval europe, be a drow wizard in Cimmeria, be named Fred and not connected to the culture at all, be a druid who's useless indoors, be the first cleric for the returning gods. If they agreed that the world sounded interesting, then they should be able to happily play within the confines of that world's set up if the DM considers their proposal and decides that it really doesn't fit, or be able to live with the logical repurcussions if the DM says ok but explains what those might be. As such I find it odd to have something be objectionable just because it isn't some iteration of the entire kitchen sink.