I have strong feelings about this, and the warforged are a great example.
In Eberron, being a warforged means a great deal, it's immensely tied to the lore. You were created as a living weapon, not a sentient being, by House Cannith. Veterans (which is many, many people) may feel horror at seeing you, or perhaps you're like their favorite tank, or that you can't actually have real emotions because that would mean that what they did during the Last War would haunt them. You very likely sold to one of the five nations and used in the Last War. The Treaty of Thronehold which ended the Last War also closed down all the Creation Forges, a slow genocide against your people. You have no culture of your own, just the adopted soldier culture of the nation you were a piece of military materiel for.
Being a warforged in Eberron means something.
Being a warforged in kitchen sink settings: Oh look, I'm a living construct. Woo!
The Dragonmarks have vast lore tie ins. Building them into the lore of your setting, making them important, making having one a Big Deal -- then I'm fine for them in other settings. But washing away everything interesting about them except their mechanical effects just to import them I am dreadfully against.