But to say a background "doesn't work" in a specific setting is silly. The features listed, just like skills, are transferrable. They can work in a variety of settings and situations.
Bob takes that claim at face value and now requires that you add the fallen dhakani empire to your Forgotten Realms campaign and adjust goblins to match Eberron style goblins. I could go on to copy/paste backgrounds for specific dragonmarked houses, Alice expects you to add some Eberron's megacorp-like dragonmarked houses to your FR game world too.