Exactly because it's a compact hub I seriously doubt people will actually bother turning them off because it won't make much of a difference anyway. It's not an exploration focused game in a first place so what are you losing exactly by having a marker?
The joy and satisfaction of discovery.
Some of the most memorable moments in VtM:B were about simple moments of discovery, when the world made sense. Mercurio needed morphine. Where could I find some? That clinic, maybe...? Or tracking down the cult of plague bearers, figuring out where a terrified TV producer had hid, and so on. Quest markers would have ruined that for me. It would have turned an investigation into mechanically jumping through hoops like a trained circus dog.
But I guess this is one of those things that you either get, or not.